I want to know what is the difference between bacteria, virus and germs?

Many differences... Germ is a lay person's word and could be used to describe either a virus or a bacteria. It implies an infectious particle. There are many differences between bacteria and viruses including size, ability to live outside of a host, different types of reproduction, etc... The following link has some good basic information: http://www.Diffen.Com/difference/bacteria_vs_virus.