Primary and secondary cells

Although there are many different types of battery, there are two main categories of cell or battery that can be used to provide electrical power.
Each type has its own advantages and disadvantages and therefore each type of battery is used in different applications, although they can often be interchanged:

Primary batteries:  
Primary batteries are essentially batteries that cannot be recharged. They irreversibly transform chemical energy to electrical energy. When the chemicals within the battery have all reacted to produce electrical energy and they are exhausted, the battery or cell cannot be readily restored by electrical means.

Secondary batteries:  
Secondary batteries or secondary cells are different to primary ones in that they can be recharged. The chemical reactions within the cell or battery can be reversed by supplying electrical energy to the cell, restoring their original composition.