By PHP Manual Prev Next Chapter 11. Any PHP script is built out of a series of statements.
Statements usually end with a semicolon.
In addition, statements can be grouped into a statement-group by encapsulating a group of statements with curly braces. A statement-group is a statement by itself as well. The various statement types are described in this chapter. The if construct is one of the most important features of many languages, PHP included. It allows for conditional execution of code fragments.