What is SOCKS and What is SOCKS Proxy Server ?

SOCKS is short for SOCKet Secure which is an Internet protocol that routes network packets between a client and server through a proxy server. And that proxy server is thus called SOCKS proxy server. SOCKS protocol is mostly used for SOCKS proxy to bypass Internet filters to access websites and contents that are blocked by governments, workplaces or schools. So when we saying SOCKS we most time mean SOCKS proxy.

Normally speaking, there are two versions of SOCKS – SOCS5 and SOCKS4. For us end users, they are different in 2 parts :

SOCKS4 can handle protocols (like TELNET, FTP, HTTP, GOPHER, etc) eonly based on TCP whereas SOCKS5 can support both TCP and UDP. SOCKS5 is much more secure than SOCKS4, it supports user authentication whereas SOCKS4 has no such feature.

As a SOCKS proxy server, it is always combined with both SOCKS5 proxy and SOCKS4 proxy. And for many netwrok applications, users are able to choose whether to use SOCKS4 proxy or SOCKS5 proxy.