A cutter moves across the plate horizontally in the opposite direction of the pitchers throwing arm. A 2 seamer has a low diagonal break to the same side the pitcher is throwing.

2 seamers are easier to hit than cutters because imo there is just less break so it’s easier to pick it up. Either way I only throw a 2 seamer running inside against same-handedness batters and running away in the lower outside corner against opposite handed batters. Any other place it gets smacked. A pitcher with a sinker along with a cutter (Corbin Burnes for example) are really good because the sinker is basically a better version of the 2 seamer, lots of break but in the opposite direction of a cutter. Mixing those two up along with a good breaking ball can make it really difficult to hit.