SYSTEMS SOFTWARE

Systems software, often referred to as systems programs, consists of supervisory and support modules (programs) designed to coordinate the capabilities of the computer itself. These include programs such as operating systems, assemblers, debug routines, text editors, compilers, library maintenance routines, utilities, linkage editors, and I/O drivers.

Operating Systems

An operating system is a collection of many programs used by the computer to manage and control its own resources and operations. These programs control the execution of other programs. They schedule, assign resources, monitor, and control the work of the computer, allowing it to carry out tasks independently of most human intervention.

Assemblers and Compilers

Both assemblers and compilers are language translators. They are usually designed for specific machines and specific languages. They translate computer programs written in assembly language into machine language. A language translator for an assembly language is called an assembler program. Most high-level language translators are called compiler programs. These translators are designed to convert the artificial languages used by programmers, such as COBOL or FORTRAN, into a machine-usable code after it is entered into the computer.

Utilities

Utilities are programs or routines that have general application. They may be separate programs or they may be routines or programs included with the operating system to further aid the user by performing standard functions. Sort, merge, and copy programs are typical examples. Other examples are text editors to allow programmers to enter, add, delete, or change program statements; linkage editors to put together compiled programs and routines; and debug routines to help programmers find errors.

APPLICATIONS SOFTWARE

Applications software consists of programs designed to solve specific classes or types of problems. For example, word processing programs help us prepare correspondence, instructions, messages, and so on. Spreadsheet programs enable us to store and manipulate numbers in numerical tables. Database programs enable us to store and retrieve large amounts of data in various report formats. Some software is ready to use and may be purchased from retail stores and government contracts. This software is called off-the-shelf software (COTS). If COTS is not available to solve Navywide or individual user problems, the Navy may write its own programs. Some programs are designed and written by one of the Navy's central design agencies and distributed to AIS installations for use. If no Navy-developed software will solve an individual problem, you or your automated information system (AIS) installation may write a program in one of the many programming languages.