?Computer software has made a major impact in our everyday lives, even though we cannot actually see "software", we only see its results. System Software helps in running the computer hardware and computer system. Programming Software provides tools to assist a programmer to write computer programs and software using specialized language called programming language. Application Software allows the user to carry out one or more specific tasks which are not computer related. Now- a- days almost every field uses some form of application software. Without any type of software the computer would be useless. The software business has reached a major crossroads as the traditional models of development and distribution are being shattered by the mainstream adoption of software as a service and the demand for next generation virtual machine technology to support everything from enterprise architectures to new mobile appliances.