An SSL certificate provider (certificate authority) issues digital certificates to organizations or individuals after verifying their identity. These SSL Certificate Reviews can help you choose one SSL certificate provider over another. Each SSL certificate provider has different products, prices, certificate features, and levels of customer satisfaction. In order to help you separate the wheat from the chaff, you can read authentic SSL reviews for each of the major certificate providers and decide who to trust with your SSL certificate needs.
A certificate authority verifies an entity's credentials and, essentially, certifies that they are who they say they are. Once an entity's information has been verified, the certificate authority will sign it's public key using the CA's private key. Because all major certificate authorities have "root certificates" in web browsers, the entity's certificate will be linked through a "chain of trust" and the web browser will recognize it as a trusted certificate. Basically, web browser developers are saying "We trust this certificate authority and they say that this is the entity's public key so, if we use it, we know we are talking to the right entity."