A predicate function is a function that returns true or false. Meant to check something against a (series of) condition(s) and return true or false. This terminology shows up in all sorts of places. Example: ```typescript function myPredicateFunction(number: number): boolean{ return number % 2 == 0 //true for dven, false for odd } const myArray = [1,2,3,4,5]; const evensOnlyArray = myArray.filter(element => myPredicateFunction(element)); ``` **** # More ## Source - self. ## Related