Computer Software

Payroll Processing Program

Application software is written to perform a specific task or process. A Payroll Processing Program is designed specifically to calculate and manage employee salaries, which is a specific business task — making it application software. Linux, UNIX, and Language Compilers are all types of System Software because they support and manage the computer's operations rather than serving a specific user task.

Job Control Language

JCL stands for Job Control Language. An operating system understands a fixed set of commands known as JCL. These commands are used by computer users to indicate their requirements to the operating system. It is NOT 'Job Common Language' (a common wrong answer), nor is it related to Java. JCL is the way users communicate their needs to the OS.

Machine Language

A computer can directly understand only Machine Language, which consists of binary digits (0s and 1s). This is the native language of the computer's processor. Assembly language and High Level Languages (like BASIC, C, C++) need to be translated into machine language before the computer can execute them. This translation is done by programs called assemblers, compilers, or interpreters.

Mnemonic codes (abbreviations)

Assembly language, also known as symbolic language, uses mnemonic codes — short abbreviations that are easier to remember — to replace the 0s and 1s of machine language. For example, instead of writing a long binary string, an assembly language instruction like PACK is used. It does NOT use full English sentences (that is a feature of high-level languages) or mathematical formulas directly.