What is an SSL Certificate?
Public Key Encryption
Why Use HTTPS?
There are several different types of SSL certificates. One certificate can apply to a single website or several websites,
depending on the type:
Single-domain: A single-domain SSL certificate applies to only one domain (a ' domain" is the name of a website, like
Wildcard: Like a single-domain certificate, a wildcard SSL certificate applies to only one domain. However, it also includes
that domain’s subdomains. For example, a wildcard certificate could cover www.cloudflare.com,blog.cloudflare.com, and
developers.cloudflare.com, while a single-domain certificate could only cover the first.
Multi-domain: As the name indicates, multi-domain SSL certificates can apply to multiple unrelated domains.
SSL certificates also come with different validation levels. A validation level is like a background check, and the level
changes depending on the thoroughness of the check.
Domain Validation: This is the least-stringent level of validation, and the cheapest. All a business has to do is prove they
control the domain.
Organization Validation: This is a more hands-on process: The CA directly contacts the person or business requesting the
certificate. These certificates are more trustworthy for users.
Extended Validation: This requires a full background check of an organization before the SSL certificate can be issued.
How can a business obtain an SSL certificate?
Cloudflare offers free SSL certificates for any business. A website protected by Cloudflare can activate SSL with a few clicks.
Websites may need to set up an SSL certificate on their origin server as well: this article has further instructions.
More about SSL/TLS
For more on how SSL/TLS encryption works, see What is TLS? Use the Cloudflare Diagnostic Center to check if a website is
properly implementing SSL/TLS encryption.