Tips & Definitions:
A computer program (often simply called a program) is an example of computer software that prescribes the actions ("computations") that are to be carried out by a computer. Most programs consist of a loadable set of instructions which determines how the computer will react to user input when that program is running, i.e. when the instructions are 'loaded'. The term program or computer program is used interchangeably with software and software application. The term software program is redundant and should not be used.

Application software is a subclass of computer software that employs the capabilities of a computer directly to a task that the user wishes to perform. This should be contrasted with system software which is involved in integrating a computer's various capabilities, but does not directly apply them in the performance of tasks that benefit the user. The term application refers to both the application software and its implementation. A simple, if imperfect, analogy in the world of hardware would be the relationship of an electric light-an application-to an electric power generation plant-the system. The power plant merely generates electricity, itself not really of any use until harnessed to an application like the electric light which performs a service that the user desires. Typical examples of software applications are word processors, spreadsheets and media players. Multiple applications bundled together as a package are sometimes referred to as an application suite. Microsoft Office, which bundles together a word processor, a spreadsheet, and several other discrete applications, is a typical example. The separate applications in a suite usually have a user interface that has some commonality making it easier for the user to learn and use each application. And often they may have some capability to interact with each other in ways beneficial to the user. For example a spreadsheet might be able to be embedded in a word processor document even though it had been created in the separate spreadsheet application.

User software tailors systems to meet the users specific needs. User software include spreadsheet templates, word processor macros, scientific simulations, graphics and animation scripts. Even email filters are a kind of user software. Users create this software themselves and often overlook how important it is. In some types of embedded systems, the application software and the operating system software may be indistinguishable to the user, as in the case of software used to control a VCR, DVD player or Microwave oven. Generally, the user-written software genre consists of small programs, that are designed to accomplish or test one thing. These simulations and scripts usually focus on the specific goals of the writer, and lack the polish and generality of commercial applications. User-written programs usually have a short life-span. Occasionally, small user-written programs evolve into enormous applications. When user programs are generalized to meet the needs of many users, and get spit and polish, they evolve into self-standing applications. Some engineering and science simulations have grown to be millions of lines of code. Some personal business spreadsheets have grown into important corporate-wide applications. The World wide web began as a personal project to publish physics papers on the Internet, and grew to become the largest software project in the world. As user-written programs evolve and become more important, professional software engineers take over many development responsibilities.