What is CA
A certificate authority is an entity which issues digital certificates to domain names or organizations after validating them and validate the contact owner of the domain and business account.
CA is a trusted third party—trusted both by the (owner) of the certificate and by the party relying upon the certificate.
CA issues digital certificates that contain a public key and the identity of the owner. The matching private key is not made available publicly
Certification authorities have to keep detailed records of what has been issued and the information used to issue it, and are audited regularly to make sure that they are following defined procedures.
Every certification authority provides a Certification Practice Statement (CPS) that defines the procedures that will be used to verify applications.
Every certificate authority has different products, prices, SSL certificate features.