What is a Proxy Server? Types & Examples You Need to Know

By Tibor Moes / Updated: June 2023

What is a Proxy Server? Types & Examples You Need to Know<br />

Proxy Server

When you go out to buy groceries, to work, or just have a fun night, the people you meet along the way know only what information you decide to share. Your home address and ID number aren’t written on your forehead.

However, a different set of rules apply online. There, anyone could see who you are and where you’re coming from – if they’re interested enough. That’s precisely what proxy servers can help you prevent.

Most of us surf the internet without thinking about what happens in the background. In the beginning of the world wide web, this approach was understandable. After all, cyber threats weren’t such a massive factor initially and only few people considered the intricacies of privacy protection.

As the online world grew more complex, various malicious online entities followed suite. Finally, we reached a point where protecting your personal info is the greatest concern. 

But what is a proxy server precisely and how does it work? You’ll find out all about it and more in this article.

Summary

  • A proxy server, acting as an intermediary, handles requests from clients seeking resources from other servers—boosting security, privacy, and enhancing network performance.
  • Proxy servers enable anonymity by hiding IP addresses, permit content control via filters, and provide faster internet speed by caching data.
  • They’re categorized into different types, such as forward proxy (direct client-server interaction), reverse proxy (protects the identity of a server), and open proxy (publicly accessible), each serving unique purposes.

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What is a proxy server?

Simply put, a proxy server represents a gateway through which your device communicates with the internet. While this explanation is simple enough, it doesn’t really say volumes about what proxy servers do, how they function, and why you’d need one.

Let’s break it all down.

When your computer goes online, the process usually involves two devices: your PC and a router. The router supplies the network connection, and you simply plug in the Ethernet cable or hook onto the Wi-Fi signal.

Now, imagine if there was another computer hooked to the router. But that other computer isn’t drawing the connection from the router; instead, it’s supplying internet connectivity to the device.

This is, more or less, what a proxy server does. It can be a router or an entire system that handles the online traffic between you and the web.

A proxy server has its own IP address, which represents one of the biggest advantages. The IP address is important because it’s your online ID. When you visit a website, your IP address might be visible, increasing the risk of different types of cyber-crime, including hacking attacks and identity theft.

Proxy servers can prevent such risks by directing your traffic under a different IP address. In a way, this makes your computer nearly invisible online. All that a cyber-criminal would see on their end would be the proxy’s IP address, not your actual one.

That basic layer of protection is only the beginning, though. Today’s proxy servers offer a wide range of features that make your browsing sessions even safer. For example, a proxy server can filter incoming traffic or act as a firewall.

How Proxy Servers Work

As stated previously, a proxy server uses its own IP address instead of yours to communicate with websites. IP addresses count among the crucial aspects of online traffic because they allow for correct information exchange.

Simply put, when your computer sends a request to a website, the site answers to the IP address that is communicating with it. It’s not very different from exchanging letters – writing back to a pen pal would be impossible if you didn’t know where to send your reply.

With a proxy server, when you go to a URL, you’re not exchanging info with the website directly. Instead, all data is sent to the proxy server which then forwards it to and from your computer.

While this mechanism is quite straightforward, it’s hardly impressive on its own. That’s where the additional features come in.

There was a time when proxy servers only did the intermediary work which didn’t involve much more than concealing your IP address. However, the data itself still flew unhindered between the website, proxy server, and your computer.

This meant that, if you clicked on a link containing malware, you’d still get the malicious package sent to your computer unless it was protected by an antivirus program.

With additional security features in proxy servers, such unfortunate incidents became less likely. Today’s proxy servers can be genuine security powerhouses. Certain types of proxy servers might not even need help in staving off online threats.

Types of proxy servers

There are two main types of proxy servers: reverse and forward proxies.

A forward proxy server moves the information “forwards,” from your computer to the internet. On the other hand, a reverse proxy enables traffic “in reverse,” processing requests from the internet and, if deemed safe, passing them through to your system.

Both types monitor traffic in much the same way, with the direction being the main difference. Like a forward proxy, reverse proxies will pass any information through a firewall. Both forward and reverse proxy servers will also check if the requested data is already cached on the proxy server. If it is, the proxy will pass the data along without communication with the main web server.

In addition to the two main types, every proxy server can be classified according to its protocol, source, accessibility, and anonymity level.

Proxy Servers by Protocol

A proxy server can use different protocols to operate:

  • HTTP protocol

  • HTTPS

  • SOCKS

  • SIP

  • SMTP

  • FTP

  • DHCP

  • DNS

  • Smart DNS

  • CGI

HTTP and HTTPS protocols are reserved for web content. HTTP proxy servers offer only the basic service of hiding the original IP address. While the address might be hidden, all activity through this protocol is visible online.

On the other hand, HTTPS protocol allows for secure, encrypted connection through SSL. Proxy servers utilizing this protocol can be considered essentially as SSL proxy connections with the combined benefits of a proxy server and encrypted data transferring.

SOCKS protocol involves an additional third-party proxy as it allows all SOCKS5-compatible traffic. However, these types of proxy servers don’t provide advanced protection. The data passing through a SOCKS proxy won’t be encrypted and there’s no guarantee that your online behavior will remain anonymous.

SIP proxies are used exclusively for telephones. This type of proxy performs the same function for phone calls as online proxy servers do for web traffic.

An SMTP proxy server forwards or denies emails according to specific rules. You might think that this server type is sufficient to protect you from email-based attacks, but it’s actual functionality is somewhat limited.

The protocol will scrutinize the web server and source address from which an email originated. It can even check the message itself for suspicious content. However, the use of an SMTP proxy will be limited to filtering out inappropriate, spam, and phishing emails. Additional solutions will be needed for complete email security.

FTP stands for “File transfer protocol,” which explains what this proxy type is used for. An FTP proxy server monitors the sender’s and recipient’s IP addresses as well as authentication. If it detects that something like a suspicious or false IP address is used, the protocol will deny file transfer.

A DHCP proxy is more of a tool for network management. It functions within a specific network, sending appropriate configurations to connected devices. This function is particularly useful when devices on a subnetwork are trying to reach their DHCP server.

DNS proxies are something you likely see online all the time without realizing. A DNS proxy server enables users to access websites via a domain name instead of an IP address. This server type checks various factors like geolocation and IP authentication and allows or blocks traffic accordingly.

If you ever found yourself unable to watch a show on a streaming service because it’s not available in your region, this could be the work of a DNS proxy. It’s also one of the main reasons why Smart DNS proxy exists.

Smart DNS has a mission to get you where you want to go regardless of geolocation. This proxy server type will forward you to the appropriate web server wherever you are – provided your request is granted.

Finally, despite its name a CGI proxy server has nothing to do with the work of computer visual artists. Instead, the acronym stands for “Common gateway interface.”

CGI proxies use web forms to conceal your data online and allow for anonymous internet use.

Proxy Types by Source

By its IP address or source, a proxy server can be at a data center, residence, or mobile.

Datacenter proxies are independent from a particular ISP. Thus, they can change the user’s IP address into an artificial one, granting online anonymity. But just because you receive a different IP address from a data center proxy server doesn’t mean you’ll be free to browse the internet unhindered.

It’s usually quite easy for a web server to recognize an address coming from a data center proxy. Once that happens, your access to the website might be denied. Still, data center proxies remain a popular solution due to their speed and affordability.

A residential proxy server is tied to an internet service provider. The different IP address you get from a residential proxy will be a real one instead of the artificial address provided by the data center proxy.

Such IP addresses seldom get flagged by web servers, representing a superior solution for anonymous internet use. The assigned addresses can be static or rotating. The former is a single IP address used every time, while the latter provides a new address with each new connection.

Rotating IP addresses from a residential proxy server are much less traceable than static. This makes rotating addresses more secure. However, whether you choose one type or the other, it’s worth noting that residential proxies are quite a bit pricier than other types.

Finally, a mobile proxy server uses an IP address from tablets, smartphones, or any other device that utilizes mobile data. For the purpose of the address, it won’t matter whether the device works on 3G, 4G, or 5G technology.

Proxy Servers by Accessibility

In terms of accessibility, a proxy server can be public or private.

An open, shared, or public proxy server represents a genuine “internet for the people” solution for anonymous browsing. These servers are free to use for anyone, but, aside from anonymity, users tend to get just a bit more than what they paid for – or want.

A shared proxy is plagued with several issues ranging from inconvenience to severe security risks. Firstly, these proxies are usually crowded with users, leading to slow load times and general lag.

Secondly, a public proxy server isn’t particularly safe. Any sensitive data you share over such proxies might be compromised.

In contrast, private proxy servers offer exclusive access to a unique IP address, and their pricing can be exclusive as well. Such a dedicated proxy provides greater online security that often justifies the considerable price.

Proxies by Anonymity Level

Proxies may fall into three anonymity levels: high anonymity proxies, anonymous proxy servers, and transparent proxies.

A high anonymity proxy boasts the greatest level of online security. Of course, the user’s IP address is hidden online, but the server also uses the principle of residential proxies, i.e., assigns addresses that likely won’t be flagged.

In addition, a high anonymity proxy will utilize the rotating principle to ensure the greatest online privacy possible.

Anonymous proxy servers are the next level down. These proxies report different geolocation to the web servers, essentially “distorting” their IP address. This earns the proxy type the alternative name of distorting proxy.

Due to its manipulation of geolocation data, a distorting proxy server is a popular solution for users who want to access location-restricted content. Yet, this functionality can be compromised since the proxy will identify itself as such to the web server and might be prohibited from accessing the specified URL.

The famous TOR browser is likely the best-known example of anonymous proxy use. In the case of this browser, traffic is repeatedly encrypted and decrypted, as well as cycled through various servers.

Transparent proxies are the third level of anonymity. As is apparent from the name, this level offers no anonymity. Instead, transparent proxies are used mostly to filter websites, making them an excellent tool for schools and other organizations.

How a Proxy Server Enhances Your Online Security

So far, we’ve established how a web proxy server keeps your IP address hidden online. This ability can be paired with a firewall, web filters, and additional third-party SWG and email security solutions. At that point, you get a barrier that keeps most digital wrongdoers far away from your computer.

Here’s a breakdown of these powerful internet security features.

Firewall Keeps Out Unwanted Traffic

You’ve undoubtedly heard of firewalls as a must-have security feature. But you might not know how a firewall functions as a part of a proxy server.

A firewall can come in software and hardware variants. Its main task is to keep watch of whatever tries to access your system and block traffic from unrecognized sources.

Of course, a piece of technology can’t know which sources are good or bad by itself. To make that distinction, a firewall uses a set of rules. In other words, a firewall must be configured to let through specific traffic and recognize friendly IP addresses.

Obviously, this function is paramount to stave off any online bandits trying to break into your computer or network. But if a data package gets past the firewall, there’s no way of telling whether everything in the package is actually safe.

After all, you might visit an internet address that contains malicious links or malware.

That’s precisely why web filters exist.

Web Filters Take You to the Safe Places of the Internet

A web filter doesn’t monitor inbound online traffic. Quite the contrary, it checks whether the web pages you visit are safe or not and allows or blocks outbound traffic accordingly.

Web filters have two modes of operation: one that lets traffic through only towards specific addresses, and the other, which restricts access to sites based on predetermined standards.

In the first case, it’s possible to create a list of trusted websites. The filter will provide unhindered traffic with those sites exclusively – all other communication will be blocked. This solution can be excellent for a closed or private network but would be a nuisance for personal browsing.

The other solution is much more flexible while maintaining a high level of online security.

A web filter can be set up to inspect URLs for certain keywords, denying access to those that contain forbidden terms. Furthermore, the filter will, upon request, do the same search on the site’s content.

As a result, the chances of landing on risky web pages are reduced significantly. In addition to this, a good web filter can also block outbound information packages to protect any sensitive data from getting on the internet.

SWG: A Filter on Steroids

Where a web filter can block outbound traffic to suspicious sites, a secure web gateway (SWG) restricts all such traffic – inbound as well as outbound.

There’s a good reason why the term “gateway” is in the name SWG. If you imagine your internet security as a castle, the proxy server would represent the walls. The SWG would be the gateway through which only select messengers can come in or out.

In some sense, an SWG does a similar job as a firewall. However, while firewalls check data packages on a network level, SWGs do this on the application level. This level doesn’t refer to application in terms of apps on your device, though. In this sense, “application” refers to device identification, inter-device authentication, specific protocols and syntax, and data presentation.

Email Security Keeps Your Communication Clean

Proxy servers can integrate several levels of email security. With this step, it’s possible to close one of the most frequently exploited online security gaps.

The issue with email is that, while your IP address might be hidden, the email service must remain relatively open. In particular, email traffic can’t be blocked in the same way as regular internet traffic. However, it can be made safer through email-specific methods.

The two most powerful solutions for email protection through proxy servers are email encryption and a secure gateway.

Email encryption does precisely what the name says: sends out emails as encrypted data. Besides preventing the data in intercepted emails from getting into the wrong hands, encryption can also be vital for organizations that need to comply with certain security standards.

Secure email gateways do for emails what an SWG does for general internet activity. These gateways scrutinize and filter messages using specific rules. This way, the gateway ensures no suspicious emails can get through and potentially jeopardize your system.

Examples of Proxy Server Use

Besides security and online privacy, proxy servers can offer various benefits, including:

  • Data can be encrypted via SSL proxy.

  • Proxy-enabled compression can improve bandwidth and boost performance.

  • The workload can be distributed between servers for load balancing purposes.

  • A proxy can cache HTML, images, videos, and other static content, preventing server overload and increasing delivery speeds.

  • Proxies can be used to set up a content delivery network. This represents an advanced type of caching that allows the user to access the content from the closest data center.

  • Access to specific content may be restricted through filtering.

Use Proxies for a Stable and Safe Online Experience

The right type of proxy server can represent a massive improvement in your internet usage. Depending on your requirements, you can get a proxy that all but guarantees online anonymity, protects you from data breaches, or simply allows you to control internet traffic on your network.

Proxy services can prove immensely practical and convenient. Now that you know the ins and outs of proxies, you’ll be more likely to choose the right server type for your needs.

How to stay safe online:

  • Practice Strong Password Hygiene: Use a unique and complex password for each account. A password manager can help generate and store them. In addition, enable two-factor authentication (2FA) whenever available.
  • Invest in Your Safety: Buying the best antivirus for Windows 11 is key for your online security. A high-quality antivirus like Norton, McAfee, or Bitdefender will safeguard your PC from various online threats, including malware, ransomware, and spyware.
  • Be Wary of Phishing Attempts: Be cautious when receiving suspicious communications that ask for personal information. Legitimate businesses will never ask for sensitive details via email or text. Before clicking on any links, ensure the sender's authenticity.
  • Stay Informed. We cover a wide range of cybersecurity topics on our blog. And there are several credible sources offering threat reports and recommendations, such as NIST, CISA, FBI, ENISA, Symantec, Verizon, Cisco, Crowdstrike, and many more.

Happy surfing!

Frequently Asked Questions

Below are the most frequently asked questions.

Are a VPN and proxy the same?

Proxies and VPNs have much in common. However, a VPN is more secure as its servers are proxy servers with added encryption.

How to install a proxy server?

The easiest way is to buy a VPN service. For a few dollars per month, you’ll get access to a wide range of VPN servers, which are proxy servers with an added encryption layer.

What type of proxy Is the best?

The best type of proxy will depend on the intended use. A Virtual Private Network would be the best choice if security and anonymity are your main concerns.

Author: Tibor Moes

Author: Tibor Moes

Founder & Chief Editor at SoftwareLab

Tibor has tested 28 antivirus programs and 25 VPN services, and holds a Cybersecurity Graduate Certificate from Stanford University.

He uses Norton to protect his devices, NordVPN for his privacy, and Proton for his passwords and email.

You can find him on LinkedIn or contact him here.