Another important part are the proxy servers, where they actually act as an intermediate server between the client and the actual server. They are usually used for security purposes and anonymity. As soon as the client creates a request, the request reaches the proxy server, and the proxy server is then in charge of determining what to do. This way, the client does not see the actual server and cannot attack him directly or cause any other bad things. Furthermore, servers usually use cache memory. Caching is something that YouTube uses, big companies use, and if you want fast responses, it is crucial. The basic idea behind caching is that a chasing server has the files that you request and can respond back to you very fast. They are usually not so big and cannot store everything. Imagine them as another server that stands in front of the actual big one, where only the top 100 requests are stored. It is like a shield, where you first hit the cache server and then, the actual server. If you search or request something that is already requested by many users, you will probably find it there and get a fast response. If the proxy server does not have the file, it creates a request from the web server and responds but in this case, you will have to wait a bit longer. In the following figure, we can see that the client requests something from the server but he actually communicates with the proxy server. The proxy server is in front of the main server and acts like a firewall or another security layer.