In cryptography, a pre-shared key is a shared secret which was previously shared between the two parties using some secure channel before it needs to be used.

Is a pre-shared key the same as a password?

A pre-shared key is basically just a shared secret or password that is used to authenticate an individual attempting to join a wireless network (no username or identification or than the key is required).

What is the purpose of the pre-shared key?

Wi-Fi Protected Access Pre-Shared Key or WPA-PSK is a system of encryption used to authenticate users on wireless local area networks. It's typically utilized by telecom companies for end user access in home local area networks.