---
title: Basic Syntax
---
# Basic Syntax
A PHP script can be placed anywhere in the document.
A PHP script starts with ``
Below, we have an example of a simple PHP file, with a PHP script that uses a built-in PHP function "echo" to output the text "Hello World!" on a web page
````
My first PHP page
````
The output of that would be :
````
My first PHP page
Hello World!
````
#### Note: PHP statements end with a semicolon (;).
# Comments in PHP
PHP supports several ways of commenting:
````
````
# PHP Case Sensitivity
In PHP, all keywords (e.g. if, else, while, echo, etc.), classes, functions, and user-defined functions are NOT case-sensitive.
In the example below, all three echo statements below are legal (and equal):
````
";
echo "Hello World!
";
EcHo "Hello World!
";
?>
````
### However; all variable names are case-sensitive.
In the example below, only the first statement will display the value of the $color variable (this is because $color, $COLOR, and $coLOR are treated as three different variables):
````
";
echo "My house is " . $COLOR . "
";
echo "My boat is " . $coLOR . "
";
?>
````