Program

Program or Software is a group of computer instructions which have sort.

With the program computer can do something like a word processor. In modern computer, computer can do many instructions without a mistake and the process doesn’t need much time, the computer can execute billion of instruction every second.

In most computers, individual instructions are stored as machine code with each instruction being given a unique number (its operation code or opcode for short). The command to add two numbers together would have one opcode, the command to multiply them would have a different opcode and so on. The simplest computers are able to perform any of a handful of different instructions, the more complex computers have several hundred to choose from—each with a unique numerical code.

All of code or symbol which computer process as appliance communicates, as a way to submit the human think to the computer in the form of commands is a Programming Language.
There are three kind of Programming Language, they are :

1. Machine Code
Machine Code A language that only have ‘0 and 1’ codes or ‘Blaze and Extinct’.
Example : Apple 6502

2. Low Level Language
It is a language that has codes too, but no longer use ‘0 and 1’ , this language use alphabets.
Example : Assembly Language

3. High Level Language
In this language, language that in use has come near human languages, because the commands in this language are sentences which represent words in English.
Example : BASIC (Beginners All-purpose symbolic Instruction Code), COBOL (Common Business Oriented Language), FORTRAN (Formula Translator), Pascal, etc.

From Various Reference