SOCKS5 works one level below the web. It does not look at what is inside a connection; it simply carries it. That makes it suitable for programs that are not browsers, and it can resolve site names on the proxy side, so your own network never learns which sites were looked up.
Not every program handles SOCKS5 with a login. Chrome, for example, accepts a SOCKS5 proxy only without a username and password. When SOCKS5 gives trouble, the HTTP port reaches the same addresses. On PiratProxies the residential SOCKS5 port is 1080, with the same username and password as HTTP.
Read next: HTTP vs SOCKS5 proxies: which port to use