Conditions

$num1 = 15. $num2 = 12. $num3 = 27. $num4 = 10. $num5 = $num1 + $num2, which is 27. $a = 7

$num2 is less than $num1. This message only appears if the statement is correct.

This message appear if $num3 is equal to $num5

a is 7

If else statements are straightforward. If the If statement is false it will execute the false code. Vice versa for true.
With the elseif statement, they are looking for specific conditions. You can assign any condition so long it doesn't break the code. We did that earlier if you have the php file.
Switch case is similar to elseif statements.Switch case makes the php code look more cleaner. This preferable to use compared to if, else, and else if statements.