In PHP, a file structure refers to the organization of code within a PHP file. A typical PHP file structure includes the following elements:

1. Opening PHP tag: The opening PHP tag is used to indicate the start of PHP code in a file. It is written as <?php.
2. PHP code: This is the main body of the PHP code, where you can write your PHP statements, variables, functions, and so on.
3. Closing PHP tag: The closing PHP tag is used to indicate the end of PHP code in a file. It is written as ?>.

Here is an example of a simple PHP file structure with example:

<?php
// PHP code goes here
$name = "John";
$age = 30;
echo "My name is $name and I am $age years old.";
?>

In this example, the opening and closing PHP tags are used to enclose the PHP code that is being executed. The PHP code in this example consists of a few variables and an echo statement, which prints a string to the screen.