HTTP (Hypertext Transfer Protocol) is the basic protocol browsers use to request and receive web pages, but it sends data in plaintext that network observers can read. HTTPS (Hypertext Transfer Protocol Secure) is HTTP protected with TLS (formerly SSL) encryption, so traffic between the browser and the site is harder to intercept or alter. HTTP typically uses port 80; HTTPS uses port 443, and modern browsers mark sites without HTTPS as not secure.
