Answer ok so criteria is the standard by which something is judged or assessed ( another word for judged). And constraint or limits or restrictions for example if your mom or dad tells you, you cant play on your phone at 12 pm thats a restriction couse you cant do that at that time. Its important to use these at the beginning of a project because that way the project your doing would be correct and successful. if you dont use it then it might be wrong or not successful.
Explanation: Hope it helps :)