What is the significance of the error message "Parse error: syntax error, unexpected 'return' (T_RETURN)" in PHP programming?

The error message "Parse error: syntax error, unexpected 'return' (T_RETURN)" in PHP programming indicates that there is a syntax error with the 'return' statement in the code. This error typically occurs when the 'return' statement is used outside of a function or method. To solve this issue, make sure that the 'return' statement is only used within the body of a function or method.

// Incorrect usage of return statement outside of a function
return "Hello World";

// Corrected code with return statement within a function
function sayHello() {
    return "Hello World";
}
echo sayHello();