What is the significance of the error message "Parse error: parse error, expecting `T_STRING' or `T_VARIABLE' or `T_NUM_STRING' in..." in PHP code?

The error message "Parse error: parse error, expecting `T_STRING' or `T_VARIABLE' or `T_NUM_STRING' in..." indicates that there is a syntax error in the PHP code, usually due to missing or incorrect usage of strings, variables, or numeric strings. To solve this issue, check the line mentioned in the error message for any missing or misplaced strings or variables, and ensure that they are properly formatted.

// Incorrect code causing parse error
$name = John;
echo "Hello, $name!";

// Corrected code
$name = "John";
echo "Hello, $name!";