P stands for Parenthesis. Which means in a numerical expression you must do the sums that are in parenthesis first.
E stands for exponents. Which means a quantity representing the power to which a given number or expression is to be raised.
M stands for multiplication. Which means after exponents and parenthesis you must do th multiplication
D stands for division which means after multiplication you must do the division
S stands for subtraction which means after addition you must do the subtraction
For example if there is no multiplication we will skip to the next step. After doing all of these steps you will get your answer and that's what PEMDAS stands for .