How do I change from one branch to another ?

Going from one branch to another consists of using the checkout command ; alternatively you can use the switch command.

Considering this timeline and that you are on main branch :

A -- B -- C -- D (feature-X)
		    \
		    (main)HEAD

doing :

git checkout feature-X

does the following :

A -- B -- C -- D (feature-X)HEAD
		    \
		    (main)

What is the difference between checkout and switch ?