A computer can act on the behalf of other computers to request content from the Internet or an intranet. Proxy Server is placed between a user’s machine and the Internet. It can act as a firewall to provide protection and as a cache area to speed up Web page display. Proxy server is a computer that sits between a client computer and the Internet, and provides indirect network services to a client. It may reside on the user’s local computer, or at various points between the user’s computer and destination servers on the Internet. A proxy server intercepts all client requests, and provides responses from its cache or forwards the request to the real server. A client computer is connected to the proxy server, which acknowledges client requests by providing the requested resource/data from either a specified server or the local cache memory. Client requests include files or any other resources available on various servers.
Basic Overview of Proxy Server
Basically proxy server plays an intermediary between the client computer and the server computer. The clients usually take the help of proxy server for requesting any files, any web pages or any other resources. The proxy server acts as an identification shield between the server and the client machine.
A proxy server, also known as a “proxy” or “application-level gateway”, is a computer that acts as a gateway between a local network (e.g., all the computers at one company or in one building) and a larger-scale network such as the internet. Proxy servers provide increased performance and security. In some cases, they monitor employees’ use of outside resources.
A proxy server works by intercepting connections between sender and receiver. All incoming data enters through one port and is forwarded to the rest of the network via another port. By blocking direct access between two networks, proxy servers make it much more difficult for hackers to get internal addresses and details of a private network.
Figure: Proxy Server
How Proxy Server works?
Normally, if a PC is directly getting connected to the internet then the user is able to access the web services without any restriction. If there is a proxy server installed on a computer network, the data transfer occurs only through it. Every time user is trying to access the internet they have to send a request to the proxy server and this server is going to forward its request to the web server. Now, the web server will send this data to the proxy server and then the server saves this data in its local cache and provides it to the user in a network.
So like this, in next time if some request for the same data. The proxy server have not going to forward the request to the internet. Instead of this, it will send the data to the user from its local cache. In this way, the proxy server saves network bandwidth and improves network performance
Types of Proxy servers
Proxy servers are classified into several types based on purpose and functionality. Some of the most common types and their uses can be described as below:
Forward Proxy: Forward proxies are proxies where the client server names the target server to connect to. Forward proxies are able to retrieve from a wide range of sources (in most cases anywhere on the Internet). The terms “forward proxy” and “forwarding proxy” are a general description of behavior (forwarding traffic) and thus ambiguous except for Reverse proxy.
Open Proxy: An open proxy is a forward proxy server that is accessible by any Internet user. Gordon Lyon estimates there are “hundreds of thousands” of open proxies on the Internet. An anonymous open proxy allows users to conceal their IP address while browsing the Web or using other Internet services.
Reverse Proxy: A reverse proxy is a proxy server that appears to clients to be an ordinary server. Requests are forwarded to one or more origin servers which handle the request. The response is returned as if it came directly from the proxy server
Advantages of Proxy Server:
There are lots of advantages in using a proxy server. Following are the list of advantages:
- Proxy server helps the clients to protect their important information from getting hacked by hackers.
- A proxy server is also used in bypassing blocked websites. It happens many a time that in some offices or schools or in any organizations they blocked some of the websites for their own reasons. Also, many websites have some country restrictions. In those cases, if you want to access those websites, the proxy server will help you in doing that.
- The proxy server is also used to enhance the security and privacy level of the client’s device while doing surfing using different proxies.
- Proxy server many times used for speeding up the browsing and access data, because of their good cache system.
- As the cache system of the proxy server is very good, when you access any websites using a proxy server, it is having the chance to store your desired data in their cache system. And as a result, you can access them whenever you want.
Disadvantages of Proxy Server:
- The cache system of the proxy server is very good and active, in many cases, it may happen that you passwords, or your browser websites or any secured data can easily be looked by the proxy service provider. So it is advisable to go for a dedicated or paid one.
- It happened many a time, although using the encrypted connections or network, your data or information can be leaked using the technique of TLS and SSL encrypted connections.
- Again as we have come to know above that, with the help of proxy server any blocked websites can be accessed. So it is found many times that any blocked and offensive websites which are not good for students are being accessed.
 “What is a proxy server?” available online at: https://kb.iu.edu/d/ahoo
 “What is a proxy server?” available online at: https://www.iplocation.net/proxy-server
 “FTP and proxy Server”, available online at: http://www.idc-online.com/technical_references/pdfs/data_communications/Ftp_and_Proxy_server.pdf
 “What is Proxy Server and How it Works | Advantages And Disadvantages Of Proxy Server”, available online at: http://www.learnabhi.com/proxy-server/
 “Proxy Server – It’s Advantages & Disadvantages”, available online at: https://www.rswebsols.com/tutorials/technology/proxy-server-advantages-disadvantages