Https is refered to http over TLS. 

TLS is abbreviation of "transport layer security". It is desigined to protect transporting messge from being eavesdropped, tampered and pretended. It‘s made up by two parts, TLS handshake and TLS record.

The transporting process

client connect to server by port 443

Asymmetric cryptography (Public key cryptography) and symmetric cryptography

There are two kind of cryptography to use in TLS to encrypt message.

Asymmetric cryptography like RSA generate a paire of keys, public key to encrypt and private key to decrypt.

Symetric ctyptography use the same key to encrypt and dectypt.

CA 

an authority angent to published certificate which is used to transport publick key.

Types of cetificate

• EV or Extended Validation SSL certificate
• OV or Organization validation SSL Certificate
• DV or Domain validation SSL Certificate (Standard SSL)

reference

http://www.ruanyifeng.com/blog/2014/02/ssl_tls.html

the introduction of https and tls(ssl)