A fault is a crack in which rocks move and slide past each other. Movements along a fault can be up, down, or side ways, depending on the type of stress.
If you don't know what stress is, let me explain. There are three different types of stress. These are compression,tension, and shearing.
Shearing is a kind of push pull movement like scissors.
Compression is when pressure is being pushed in, for example, squeezing playdoe between your hands.
And finally tension, this is when the rock is being pulled apart, like when you pull bubble gum from your teeth.
Now back to faults. There four different types of faults. these are normal faults, reverse faults, lateral faults and thrust fault.
Lets start with a normal fault. Faults consist of hanging wall and a foot wall. Stress can cause the hanging wall or the foot wall to move up or down. In a normal fault the hanging wall moves down. This is caused by tension. To help you remember this, think of hanging up your clothes, it is normal for your clothes to fall dawn off of the hangers, so in anormal fault the hanging wall moves down.
Next we will talk avout a reverse fault. A reverse fault is just the opposite. This is when the hanging wall moves down. This is caused by compression. To help you remember this, it is reverse for your clothes to fly up to the cieling when you hang them up.
Now lets learn about the lateral fault. This is when the hanging wall and foot wall move side by side. It is usually the cause of an earthpuake along a fault. Like when you spueeze your hands thogether and try to move one forward. And you know that when one hand moves, It moves!
And finally thrust fault. A thrust fault is when compression causes the hanging wall to slide ovr the foot wall. This may cause a subduction zone, which is where rock dives into the mantle ( hot burning lipuid like substance under the crust) and is eatin up by it.
Well, that's about allyou really need to know about faults. Hopefully you can use the information you got from this.