i have not understand stoichiomestry

Chemical stoichiometry deals with the determination of quantities of reactants or products of a chemical reaction. The word “stoichiometry” is derived from greek work “stoichion” means element and “metry” means measure. Stoichiometry is divided into two subsections.

• Gravimetric analysis and
• Volumetric analysis.

The problems on gravimetric and volumetric analysis can be solved using two well known concepts i.e.mole conceptand equivalent concept. [Stoichiometry] But generally, the problems on gravimetric analysis are solved using mole concept since mole concept is easier to apply in such cases while problems on volumetric analysis are solved making use of equivalent concept since it does not require the use of balanced chemical reaction.
However, there is no hard and fast rule that these guidelines should be followed strictly. We can make use of equivalent concept of gravimetric problems and mole concept for volumetric problems.