SSL use public-key cryptography to secure session key, while the session key (secret key) is used to secure the whole session taking place between both parties communicating with each other.
The SSL protocol was originally developed by Netscape. Version 1.0 was never publicly released; version 2.0 was released in February 1995 but “contained a number of security flaws which ultimately led to the design of SSL version 3.0.” SSL version 3.0, released in 1996, was a complete redesign of the protocol produced by Paul Kocher working with Netscape engineers Phil Karlton and Alan Freier.
All of the other answers are incorrect