JavaScript automatically converts types when needed. This is implicit coercion:
"5" + 3 // "53" (number becomes string)
"5" - 3 // 2 (string becomes number)
"5" * 2 // 10 (string becomes number)
true + 1 // 2 (true becomes 1)
Notice the inconsistency: + with a string concatenates, but -, *, / convert to numbers. This catches many beginners off guard. Learn these rules or avoid mixing types.