What is the difference between the "+" and "." operators when concatenating strings in PHP?

The "+" operator in PHP is used for arithmetic operations and cannot be used for concatenating strings. Instead, the "." operator should be used to concatenate strings in PHP. Using the "." operator allows you to combine two or more strings together to create a single string.

// Incorrect way to concatenate strings using "+"
$string1 = "Hello";
$string2 = "World";
$result = $string1 + $string2; // This will result in an error

// Correct way to concatenate strings using "."
$string1 = "Hello";
$string2 = "World";
$result = $string1 . $string2; // This will result in "HelloWorld"