How can using proper variable naming conventions improve code readability and maintainability in PHP?

Using proper variable naming conventions in PHP can improve code readability and maintainability by making it easier for other developers to understand the purpose of each variable. By using descriptive names that indicate the data type or purpose of the variable, code becomes more self-documenting and easier to maintain. Additionally, following a consistent naming convention across the codebase can help developers quickly identify variables and understand their context within the code.

// Bad variable naming convention
$a = 10;
$b = 20;

// Good variable naming convention
$firstNumber = 10;
$secondNumber = 20;