In Mortal Kombat X, there is a separate button for throwing, thanks to which you do not need to press two punch buttons to do that. When you press the throw button, you always throw the opponent behind. If you want to perform a forward throw, you additionally need to press the > direction button. Throws can be interrupted, by pressing a punch or a kick button, depending on the direction. This may seem confusing, at first, but you can make things out. For example, if you are cornered by the opponent, he will rather not want to make things easier for you and throw you back towards the center of the arena. It requires a lot of practice, to interrupt throws and it requires appropriate timing.
The option to throw in both directions may be useful. Imagine that you are pressing the opponent against the wall. In such a situation, there is no point in throwing them back into the center of the arena so, it is better to throw them at the wall. On the other hand, if it is you that is pressed against the wall, throwing the opponent back (at the wall), puts them in a distadvantageous situation, because you change places.
You can grab the opponent and interrupt your own throw with Block - this wins you several extra frames to perform more moves. This way, you can confuse the opponent, a bit, who will then only be able to block. This effect is called Hit Stun - it prevents the opponent from landing their own blow.
What else needs attention, while blocking? If you crouch to avoid the opponent's throw, they will be unable to grab you (unless the specific character variant allows that). However, if you perform a crouching block, the throw will be performed - you need to pay attention to that.