Computer Programming Languages

The computer programming languages are divided into three groups:
1)  Low-Level Languages
2)  Middle-Level Languages
3)  High-Level Languages

1) Low-Level Languages
Low-Level computer programming languages are easy for computer to understand but difficult for humans to understand. In fact they are easier than binary language but are very closer to it so an ordinary user can’t access it very easily. Machine Language and Assembly Language lie in the category of low-level languages.

2) Middle-Level Languages
Middle-Level languages are more easier and understandable than the low-level languages. They you English like syntax. A Language, B Language, C Language and C++ lie in the category of middle-level languages.

3) High-Level Languages
High-Level Languages are the most easier computer programming languages. These are easier for humans but difficult for computer to understand. These languages also use English like syntax but in very clear and easier way. Languages like, GW BASIC, Pascal, COBOL, FORTRAN, ALGOL etc lie in the category of high-level languages.

Tangible Parts Of The Computer

Tangible Parts or we can say physical parts of a computer, By word physical we can get the idea, "Parts That we can touch". There are four type of computer hardware, which are given below;

1.  Input devices
2.  Output devices
3.  Storage devices
4.  Processing Devices

Input devices:
The input devices are those devices, through which we can enter data into the computer. For examples Keyboard, Mouse, Trackball, Joystick, Light pen, Touch sensitive screen, Scanner, OMR, OBR, OCR etc.

Output devices:
The input devices are those devices, through which we can see our required output.
There are two types of output devices,

• Soft copy output devices whose output is intangible. Example: CRT Monitors, LCD Monitors, ETC.
•  Hardcopy output devices whose output is tangible. Example: Printers and Plotters There also some audio output devices Example: Speakers.

Storage devices(Primary)

Processing Devices:

These devices convert the input into output. Processor is the processing device in the computer. It is the brain of the computer. Every CPU has the Four main units, which are 

• CU (Control Unit)
• MU (Memory Unit)
• ALU (Arithmetic and Logical Unit)
• FPU (Floating point unit)

System Software And Its Types

The system software is basically a soft ware that enables the application soft ware to interact with computer and helps the computer to manage its internal as well as external resources. System software is needed to run application software, however the reverse in not possible. There are three basic types of system software,

1. Operating System
2. Utility Programs
3. Language Translator

Operating System:
This is the principal component of system soft ware in any computer system. It manages the basic operation of computer system. The Examples of OS are DOS, Windows, UNIX, LINUX etc. Operating system performs the following functions given below.

• Booting
• Managing storage media
• Provide User Interface
• Managing computer resources
• Managing files
• Managing tasks

Booting:
The Operating system begins to operate as soon as you turn on or boot the computer. The term booting refers the process of loading an operating system into main memory from hard disk.
Managing storage media:
To manage the hard disk, floppy disk. For example to format disks.
User Interface:
User interface is basically user controllable part of the operating system that allows you to communicate or interact with it. There are four types of user interface, which are given below.

• Command driven user interface (CUI) 
• Menu driven user interface(MUI)
• Graphical user interface(GUI)
• Network user interface(NUI)
• Command driven user interface(CUI):

Managing computer resources:
The operating system also manages the computer resources such as to manage main memory. It keeps track of location with in main memory where the programs and data are stored.
Managing files:
The files which are located on hard disk, the operating system allows you to find them. If you copy, rename, or delete the files the operating system manages such changes.
Managing tasks:
A computer is required to perform many different tasks at once. For Example in MS Word it accepts input data, stores the data on a hard disk and prints out a document.


Utility Programs:
Utility programs are special programs offered that either enhance existing functions or provides those services which are not provided by system soft ware. The principal services offered by utilities are following,

• Backup
• Data Recovery
• File Defragmentation
• Virus protection
• Data Compression

Language Translator:

A language translator is a soft ware that translates a program written by a programmer in a language such as C, HTML into machine language (0, 1) which the computer understands. 

There are three types of language translators are there, which are given below.

• Compiler
• Interpreter
• Assembler

Compiler:

This translates high level language program into machine language. This coverts whole program line by line but executes whole program at once. It is also called before compilation.

Interpreter:

This translates high level language program into machine language. This converts and executes whole program line by line. It is also called immediately execution.

Assembler:

Assembler interprets assembly language program into machine language.

Classification of computer according to Size,Purpose and Function

According to size:
According to size, there are four types of computers,

Micro computers:
Size, speed and cost of the micro computers are lower than the mini, main frame and super computers.
Also called PC or Personal Computers, this computer is mostly used in homes and in many educational institutes etc.

Mini Computers:
Size, speed and cost of the micro computers are lower than the main frame and super computers but higher than the micro computers.Also called Macro computers, this is computer used in Financial institutes

Main Frame Computers:
Size, speed and cost of the micro computers are lower than the super computers and greater than the micro, mini and main frame computers.

Super Computers:
Size, speed and cost of the super computers are greater than the micro, mini and main frame computers.

According to purpose:
Two types, which are; General and Special purpose
General purpose: Which performs more than one different function and used generally.
Special purpose: Which, performs one special function like ATM machine

According to function:
Three types which are; analog, digital and hybrid
Analog computers: Which are continues in nature and they use the analog technique.
Digital computers: Discrete in nature, always gives the accurate value.
Hybrid: The combination of analog and digital computers.

Types Of Primary Storage Devices For A Computer

Primary Storage Devices store data temporary. There are two types of primary storage devices,

(1) RAM (Random Access Memory)
(2) ROM (Read only Memory)

(1) RAM:
It is a volatile memory. This is called random access memory because nay piece of data available inside the memory can be accessed directly or randomly. RAM may be conventional and extended. Conventional memory is also called Base memory. First 640 Kilo Bytes of the total memory is called conventional memory is called Conventional memory, where the Operating system resides. Memory besides the conventional memory is called Extended Memory.
The RAM may be of following types, which are given below.

• DRAM
• SRAM
• SIMM
• DIMM

(2) ROM:
This is called read only memory because we can only read the contents of memory but we can not write on the ROM chip. This basically contains Display messages from the manufactures.
Run the POST (Power on Self Test), which checks the memory, keyboard, drives, printer and all attached devices. it perform the function of Searching for an Operating System.
It loads the BIOS (Basic Input Output System), which works with the microprocessor, for controlling the inputs and outputs. That’s why we some time called BIOS as ROM BIOS.
There are three types of ROM, which are given below.

• PROM
• EPROM
• EEPROM