Introduction to Computer : What it is ?

Current article deals with the basics of computer and programming technical.
Friends,
as we are going to discuss programming in this blog so it is essential to understand the machine where programming is done and something about programming languages.

Computer

As all know computer is an electronic machine. It not only compute,store,process data but also analyze bulk of data into fraction of seconds.
A computer basically consists of three parts viz. Input, Output and processing devices but as you are a computer engineering student so we'll not go into deep.
As we know a computer is nothing without the commands to do something from a source. Yes a source and it may be human but not necessary. A computer may work from a command by another computer but the theme is A computer always need some commands to operate and in no case it can operate without commands.
Now, this technique of writing commands for a computer or a machine is called Programming.
Lets discuss some basics of programming.

What is a programming language ?

A programming language is a set of standard commands and instructions for doing particular task(s) whether it may be a simple adding or may be a complected task.

What is syntax ?

A syntax is way of writing a command. For example in micro controller programming language (Assembly) moving is done as
MOV Destination, Source
This is just a common instruction which will move data from source to destination and it will only work if source and destination are replaced by proper addresses in my address mode of micro controller addressing.
This is Syntax.

Which languages are available for programming ?

Today huge number of programming languages are available. Depending upon the task you may choose what suits you need.
Programming languages are classified depending upon their ease. These are :

1. Machine Level Programming Languages (MLPL) or Machine Language : This is the most difficult to understand because it is written using 0 & 1 only. It runs directly on machine and hence is as fast as your mind but programming need more time in such languages.


2. Assembly Languages (AL) or Low Level Language : These are programing languages used in micro-controllers and micro processors and are written in English but not easy to understand. These are easier then Machine Languages but require more time to execute.


3. High Level Languages (HLL) : These are programming languages that are written in modern English and require measurable amount of time to execute and high performance system to operate. Examples are Object Oriented Programming Languages like Java, C#, C++ etc.


4. Middle Class Programming Languages (MCPL) : Middle level programming languages are those who stands between Assembly Language and High level languages in ease to use and time require to execute. C language is typical example of such languages.

What are constants and variables ?

Every programming languages need some memory space to store data during operation, this space is allocated in form of constants and variables.
A constant is something that remains constant during the execution of the program and a variable that can store different values at different intervals.