Arlington has software design and development firms present. Software, as opposed to the hardware, is the non-physical part of the computing system. While the hardware comprises the machinery of the computer, the software is what actually drives the many functions that one accomplishes using a computer or a computing system. Softwares can be general, such as operating systems, or specialized ones for specific purposes. They perform tasks such as calculations, organizing, documentation, etc. They are designed and marketed by various software companies, and are usually sold in the forms of preloaded CDs. Software design and development is done by IT firms in Arlington. They can do both general or specialist designs and development, based on client needs.