what is the difference between heat capacity &thermal heat capacity ? 

The heat capacity C of a substance is the amount of heat required to change its temperature by one degree, and has units of energy per degree. The heat capacity is therefore an extensive variable since a large quantity of matter will have a proportionally large heat capacity.
The specific heat (also called specific heat capacity), which is the amount of heat required to change the temperature of one unit of mass of a substance by one degree. Specific heat is therefore an intensive variable and has units of energy per mass per degree.