Creating Lists with list list takes one or more arguments and constructs a list of those items. Intuitively, we often use cons to push one item onto a list that already exists, but we use list to create a list from scratch. Append append takes two or more lists and constructs a new list with all of their elements. Intuitively, it concatenates the lists it is given. This is one of the reasons side effects are discouraged in Scheme.
Length length takes one argument, a list, and returns an integer giving the length of the list.