Hi aruna, I see perfecto has already answered your questions so i dont have anyhing else to say. But would like to know whether you are learning maya by yourself or are you learning from an institute. Maya is a vast software and involves many modules like modelling, texturing/lighting, dynamics, rigging, animation etc. Normally in a institute they will teach you all this in brief and then you can decide on specializing any one of it depending on your interest. Mahesh