There’s a crucial distinction between the balk that @Seek mentioned, though, and the base on balls or hit batter that you and I are referencing, @Call_Me_Jay. That is, with a balk, it doesn’t matter who else is on base, what bases are occupied or – crucially – whether first base is occupied or not. When a balk is called, all of the baserunners advance from their current base to their next one regardless of the occupation of any other bases.
With a walk or a hit batter, advancement of the baserunners only occurs if first base – and every base between first base and the current baserunner – is occupied. That is, a walk or a hit batter forces the baserunners along, but only because two baserunners cannot occupy the same base. But a balk doesn’t depend on which bases are occupied at the time.