Computer Language

Computer Language
The computer performs its functions based on the instructions given by the user. The set of such instructions written for a particular task is known as a computer program. Program is the set of instructions that tells the computer how to process the data, into the form desired by the user. 
The language in which a computer program is writtenis known as programming language. The programming languages are classified  as Low-level language and High-level language. 

Low-level language is further classified as Machinelanguage and Assembly language. Machine language is expressed in terms of binary numbers i.e. 0 and 1 as the processor understands binary numbers only. However,it is difficult to read and write the program in terms of 0s and 1s. The machine language code is further simplified by  converting it to the code called op code. The op code depends upon the type of processor. The program written in the op code is known as Assembly language code. During therun time, it is necessary to convert the op code into machine language so that the processorwill understand and process the code. 
The internal program that translates op code to machine code is known as Assembler. Some examples of Assembler are Microsoft Assembler (MASM), Z-80, 8085, 8086 etc. The Assembler for each processor is different. Usage of the Assembly language requires knowledge of the Assembly language and computer hardware. It is more convenient to write aprogram in a High level language, which comprises of instructions in simple English. Examples of High level language are BASIC, FORTRAN, COBOL etc. A compiler is the internal program that translates High level language to Machine language. 'Software' is another name for program. In most cases, the terms ‘software’ and ‘program’ are interchangeable. 
There are two types of software - system software and application/ utility software. Application software  is the end user software. The programs written under application software are designed for general purpose and special purpose applications. An example of application software is Microsoft Internet Explorer. 
System Softwareenables an application software to interact with the computer hardware. System software is the ‘background’ software that helps the computer to manage its internal resources. The most important system software is the operating system. The system software performs important tasks such as running the program, storing data, processing data etc. Windows XP is an example of system software.  We will be studying in detail about system softwareand application software later in this book. 
BATCH PROCESSING AND TIME SHARING 
The computer works on either batch processing or time-sharing basis. 
•  Batch Processing: In batch processing, the computer acts as a ‘stand-alone’ unit. As such, it is available for a single user. Therefore, a number of programs can be executed simultaneously. They have to stand in queue. 
•  Time-sharing: Unlike batch processing, time sharing offers simultaneous usage of computer. The computer is provided with multiple terminals from which the system can be accessed simultaneously by a number of users.