What does (v@(x:xs) mean in haskell?

Question

Whats the difference between:

(v@(x:xs)) and (v:(x:xs) 

Example function:

list [] = []
list (v@(x:xs)) = v : list xs

If i replace the (v@(x:xs)) with (v:(x:xs)) the function doesnt work.

Answer 1

v@(x:xs) matches a list with one or more, with x bound to the head, xs to the tail, and v to the entire list.

v:(x:xs) matches a list with two or more elements, with v bound to the first, x to the second, and xs to the rest.