In this course we already did use strings quite a bit. Thats because it is hard to produce easy output with out them. But C doesn't actualy have strings. Instead C uses arrays of characters. Because strings aren't normaly all the same size, C opted to null terminate all the strings. I.e the last member of the array is 0, so you don't have to know its size. When we come to the struct lecture you can, if you want, define your own strings to safe the size. But all the standart library function work only with null terminated char arrays.