In PHP applications, what are the recommended naming conventions for variables and functions to improve code readability and maintainability?

Using consistent naming conventions for variables and functions in PHP applications can greatly improve code readability and maintainability. It is recommended to use camelCase for variables and functions, starting with a lowercase letter for variables and starting with an uppercase letter for functions. This helps distinguish between different types of identifiers and makes the code easier to understand for other developers.

// Example of using camelCase naming conventions for variables and functions
$myVariable = "Hello, World!";

function myFunction() {
    return "This is a function.";
}