Certificates are used to secure communications between two computers on the Internet. A Certificate Authority's job is to:
- Try to confirm the identity of the site owner
- Issue digital certificates (in the form of text files)
- Confirm they issued the certificate and consider it to be valid if they are asked to (they can be asked to do this by browser users)
The Certificate Authority's role is to act as an independent third party that both site owners and the site visitors can trust.
The process of becoming a trusted Certificate Authority requires a lot of work, so there are only a few companies that offer certificates that are trusted globally. You can find links to some of the biggest suppliers below.