How are cells similar to bricks in a building? how are they different?

Well, the cells and bricks are similar because cells are the building blocks of life and bricks are the building blocks of buildings. Cells are necessary for life, bricks are necessary for buildings. 
They are different in the way of cells have nucleus'es (plural form of nucleus, I suppose) and other things inside it that do jobs, bricks don't have that. 

Keeps you from getting lung cancer from smoking