Sorry if this is a noob question, but how are touch controls handled?

So, I just finished the First Person shooter tutorial that Unity provides, and I wanted to export the game to android and IOS (I hope to turn it into a shock style survival horror thing)

However, this would be my first time doing touch controls, and I was wondering how that thing is handled.

I see other mobile FPSes with these fancy virtual keyboards, and I want to do that and have the game respond to external controller (MOGA or just regular PS4)

 

http://learn.unity.com/ (mobile and touch control section)

 

They're handled similar to the way you would handle buttons and axis. Just a different function with a different return type.

https://docs.unity3d.com/ScriptReference/Input.GetTouch.html