A program is nothing but some set of instructions which is executed by computer .It is perform specific task which runs through computer operating system.All the instructions are ordered form.All the instructions are run one by one.Computers are useless without program.
Suppose you want to cook something for this you need some spices ,oil,salt etc but to prepare it you need to follow the rules that means when you have to add to oil when you have to add the salt,when you need to add various spices one by one otherwise your food will be not prepared properly.Some instructions you need to follow and should be executed accordingly. Program is just like recipe which is executed by computer sequentially.
The program is stored in a place called storage area also known as memory.
The program give the instructions to the computer and one who write the program is called programmer.
The programmer giving the instructions are called program.Now the question is that in what language the programmer can write so that computer can understand the instruction and will give the output for this a language is needed that can be understand by computer it is called programming language
TYPES OF PROGRAMMING LANGUAGE
Machine Language
Computer can only understand binary form (0,1) Machine language is direct binary form a combination of 0 and 1 which computer can understand easily but to write this program you need to know the architecture of computer properly which is very difficult and all the computer not following same architecture.Machine language is very difficult .It is machine readable.It is very difficult to learn for this you need to know details about computer processor ,architecture and you need to know every thing for this which is really difficult .If any error is occurred in this language then it is also difficult to find out.For each and every architecture of a computer you need to write different language.No symbolic code or numeric code is used in this language
Assembly Language
Assembly program is readable by machine as well as human also.It is much easier than machine level language in which numeric and symbolic code can be used .
ADD 2 ,ADD 6, is used for ADDITION
SUB 3 is used for SUBTRACTION
So it is little easy for programmer to write the program.Now the problem is that how this program can be executed through computer because the computer only knows binary so i need to convert it to binary form .An assembler convert this source code and transfer it to in binary form helping computer to understand and for execution.It is easy with compare to machine level language but its having difficulty in the sense that the length of the program is large and if any error is occur in between finding out the error and rectify it is main drawback of this language.
Assembly and machine language basically low level languages.
Abstraction means hiding the complexity from the end user .Low level language having less abstraction.It is relatively non portable.
HIGHER LEVEL LANGUAGE
Higher level language is much more easier to learn and write .Program length is not so long and easily rectified if error is occurred.It is human readable but again this is not readable by computer because computer understand binary language so this high level language need to be convert to machine level language.
Compiler and Interpreter doing this function which convert high level language to the binary language .
Compiler:-It scans the whole program and translates into machine code so error is not checked line by line .It is taking much more time to analyze but taking less time for execution.
Interpreter:It checks line by line ,execute line by line .It is taking less time to analyze but taking more time for execution.
High level languages having high abstractions. All the functionalities is hided from the end user.It is portable.
SOFTWARE
Software means nothing but a set of programs ,procedures,documentation which executed by computer and perform productive task for user.It is used to operate system computer hardware and used to perform specific task.
Computer software can be divided into three categories
1.SYSTEM SOFTWARE
When we installed any operating system one software automatic loaded in the system which helps to run the computer hardware which is nothing but system software.
It is working inside the system and communicating with system hardware so no user interaction is occurred and running independently in the background. It is very fast and secure and is used for general purpose.
Low level languages are used in system software.It is not interactive and difficult to design.
When you switch on the computer system the system software starts and stops when you shut down the computer system.
It actually manages the resources like memory
Examples:-Operating system software ,communication software etc.
2.APPLICATION SOFTWARE
It is depend on user requirements.Users are interacting with application software.It is dependent on system software without system software application software will not able to run .It is used to perform productive task for the user.High level language is used in application software.It is very easy to design and very interactive for user.It is specific purpose software .How long it will run totally depend on user .Starts and stops are in users hand.
Example:Business software,education software,web browser,medical software etc.
3.PROGRAMMING SOFTWARE
Programmer are one who writes the program and to write the program some tools are required .Programming software provide such tools (text editors,compilers,interpreters)to support the programmer to write program using different languages.
IDE(Integrated Development Environment)-It merges essential tools into a software package and with the help of this programmer need not to type many commands for debugging ,tracing,compiling,interpreter etc because IDE has an advanced graphical user interface(GUI).
Example:-Notepad++(editor for windows),Coda(programming language editor for MAC)
