HTTPS
Hypertext Transfer Protocol Secure (HTTPS) is an extension of the Hypertext Transfer Protocol (HTTP) for secure communication over a computer network, and is widely used on the Internet. In HTTPS, the communication protocol is encrypted using Transport Layer Security (TLS), or, formerly, its predecessor, Secure Sockets Layer (SSL). The protocol is therefore also often referred to as HTTP over TLS, or HTTP over SSL.
HTTPS
Let's Encrypt, launched in April 2016, provides free and automated service that delivers basic SSL/TLS certificates to websites. According to the Electronic Frontier Foundation, "Let's Encrypt" will make switching from HTTP to HTTPS "as easy as issuing one command, or clicking one button." The majority of web hosts and cloud providers now leverage Let's Encrypt, providing free certificates to their customers.