Secure Sockets Layer (SSL) Certificates are used to secure information sent between web browsers and servers.
A simple analogy of how SSL Certificates work is passing a note to a friend in class. You pass the note and tell your classmates to send it to Sara. The kids continue passing the note until it gets to Sara. The problem with this, just like using unsecured http websites, is if the teacher or anyone gets the note they can simply open, read it, and leak the juicy details.
A secure way of sending the note to Sara would be sending the note in a lock box, just like using secured https websites, where you have given Sara the key to open the lock box ahead of time. This way anyone who gets the note cannot open and read it.
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