Software

Years ago, computers were huge expensive machines used mainly by large companies and universities. Since then, they have become useful everyday tools people use to share, store, and analyze information. While computers have affected the world in a very broad way, their impact in the business sector has been especially significant. Desktop computers, large mainframes, and the servers used to host Web sites are key elements in the world of e-commerce. However, contemporary computers would be useless without software.

E-commerce Web sites rely on many different kinds of software programs. Software makes it possible for e-tailers to ensure security, operate servers, manage customer relationships, allow customers to use online shopping carts and payment systems, and more. These many different pieces of software must be integrated so they work together seamlessly. This is often easier said than done. Each company needs to choose the right software programs and the right people to make them work together. In many ways, software serves as the glue that connects consumers with a company's core operations, from billing and payment to the shipping and storage.

Software itself has no physical properties like a computer's metal and plastic hardware components. Software consists of instructions that tell computers what to do. Although it's customary to view hardware and software as separate and distinct elements that work in tandem to make a computer operate, the two are actually enmeshed together at many different levels. As Paul E. Ceruzzi explained in A History of Modern Computing, "A computer system is like an onion, with many distinct layers of software over a hardware core. Even at the center—the level of the central processor—there is no clear distinction: computer chips carrying 'microcode' direct other chips to perform the processor's most basic operations."

Software normally is placed in one of two different categories: system software and applications. System software includes things like operating systems and drivers that deal with computer functions at a low level. Operating systems like Microsoft Windows, DOS, UNIX, or Linux, direct the basic functions of a computer. They provide a link between a user and the machine. Drivers are programs that support devices like printers or scanners, which are connected to the computer. Applications are software programs that users apply to various tasks, ranging from enjoyment to productivity. Applications function at a higher level than system software. Among the different kinds of applications are video games, word processing programs, spreadsheets, graphic arts programs, financial programs, and Web browsers.

Software programs are normally written in one of many different kinds of high-level programming languages like C or C++. High-level languages are much closer to actual human language than machine language, through which computer hardware accepts commands. High-level languages eventually get translated to machine language, which is numeric (consisting mainly of zeros and ones).

According to the Software History Center, contrary to popular belief, hundreds of successful software companies existed before Bill Gates and Paul Allen started Microsoft, which was the world's leading software company in the early 2000s. The industry's origin dates back to 1944 when Grace Murray Hopper and Howard Aiken wrote a program for an electromechanical computer known as the Harvard Mark I. At that time, programs consisted of sequences of holes punched on paper tape. Later, for the Harvard Mark III, Aiken developed a way for programs to be written using a keyboard. Code was written in mathematical notation and was stored on magnetic tape instead of paper tape.