letsencrypt.org - website profile

Getting Started - Let's Encrypt - Free SSL/TLS Certificates

To enable HTTPS on your website, you need to get a certificate (a type of file) from a Certificate Authority (CA). Let’s Encrypt is a CA. In order to get a certificate for your website’s domain from Let’s Encrypt, you have to demonstrate control over the domain. With Let’s Encrypt, you do this using software that uses the ACME protocol, which typically runs on your web host.