Here's a breakdown:

* Cleavage is the tendency of a mineral to break along specific planes of weakness within its crystal structure.

* Directions refer to the number of planes along which a mineral will cleave.

* What refers to the cleavage planes.

So, when you break a mineral and observe how it breaks, you're looking for the number of cleavage directions and the quality of the cleavage planes. This is a key characteristic used to identify minerals.

For example:

* Halite (salt) has perfect cubic cleavage, meaning it breaks cleanly along three directions at 90-degree angles.

* Mica has perfect basal cleavage, meaning it breaks into thin, flat sheets along one direction.

* Quartz has no cleavage, meaning it breaks irregularly in all directions.