When you cut something into flat, thin pieces, you make slices. Slices can be made from food like bread or cheese.
Slicing food is a normal thing to do in the kitchen.
Examples:
She slices the cake into small pieces.
I want two slices of bread for my sandwich.
He slices the apple with a knife.
The cat slices the cheese with a big knife.
I need a hundred slices of cheese for my sandwich.
She slices the bread very carefully so it's not too thick.