A proxy server functions as an intermediary between your device and the Internet. Any traffic directed through a proxy server will look as if it came from its IP address rather than yours. Unlike VPN servers, proxy servers do not encrypt the traffic passing through them, which saves resources and allows accepting simultaneous connections from much larger numbers of users.
The HTTP protocol is designed to interpret traffic at the HTTP level, which means it only works for web browsing. However, that is also the reason why it’s faster than either SOCKS proxies or VPN servers. This is especially useful for accessing geo-restricted media streaming, such as TV shows or sports.
These tutorials offer useful guidelines for getting started using the HTTP proxy with various browsers: from Chrome and Safari to the good old Internet Explorer. They also include tips on checking if the proxy works as expected and your IP address is hidden properly.