Code

Code

In the context of computer science, code can have two meanings. First, code is a set of symbols designed to represent an object or expression. A common example is the ASCII codes used to depict characters. Code is also written computer instruction--sequences of information that convey function.

Code as computer instruction can appear in a variety of forms. The code that a computer programmer writes is called source code. This type of code is written in whatever programming language is in use with the computing system. Source code must be converted into a language that the computer can understand--machine language--before it can be usefully implemented. The translation is accomplished by a utility called a compiler.

Source code is the only arrangement of code that is readable by humans. The source code is often supplied by a vendor in a form that cannot be read or modified by the user. In contrast, in open source languages like Linux, the source code is freely accessible and modifiable by anyone. Reflecting the explosion of programs, hundreds of source codes have been written for a myriad of programs and functions. These functions range from the operation of an individual computer or a network to computer-associated work and recreational activities.

The compiler translates the source code into object code, which can be the actual machine code or may itself require translation into machine code by other utility programs called assemblers, binders, linkers and loaders. The object code thus represents an intermediate step between the source code and the machine language. Source code can be executed, or transformed into function, once the translation into machine language is complete.

Once a code is written, it does not necessarily remain static. Evolution of code is now a designed phenomenon. In analogy with biological codes, computer codes have been termed genomes, with so-called mutation algorithms designed to facilitate random change in the code. If the random change produces a code that is functionally superior, then the mutation will hold.

Aside from their importance in computer operation, codes are also vital for other computer-associated activities. The burgeoning area of electronic business depends upon code to permit the secure electronic transmission of consumer's credit information. Periodic breaches of such codes greatly hamper these businesses, as it leaves credit card and other financial information open to pirating and illegal use.

Legal debates are arising in the United States concerning the relationship of code, particularly source code, and the First Amendment of the Constitution. This amendment guarantees the right of freedom of speech. Is a computer program a list of instructions, and so protected by the First Amendment, or is a software program just a machine and outside the coverage of the amendment? These questions, along with other code-related issues are currently under consideration among American courts and legislators.