How do they get the liquid in cans?

Question

is it with a machine or something?

Answer 1

Yes, the machines streams down the liquid into the open lid.

Answer 2

Cans are made in two parts, the bottom and the sides being one part, the top (or lid) being the second part.  So basically you start off with a metal cup that you pour the liquid into, then you put the lid on the top.  The sides of the cup are bent over the lid to keep it in place and keep the liquid in.  Machines are used to make sure the joins are really tight and nothing can get out.