Semicolons
You've probably noticed that our lines of PHP code end in semicolons (;). PHP requires semicolons at the end of each statement, which is the shortest unit of standalone code. (For example, echo "Hello!"; or 2 + 2;)
You can think of a statement is a complete PHP thought. 19 + or echo aren't complete thoughts, so you wouldn't put semicolons at the end of them!