A program is a set of instructions guiding a computer to do specific tasks. The set of instructions in the form of programs that tell a computer what task to be carried out is often called Software. The software's can be divided into System software's and Application software's.
The system software's are responsible for managing computer hardware components. Operating system, device drivers etc. are examples of system software's. The application software is intended to perform certain kind of tasks in a computer. Office, Games etc. are examples of application software.
Programs are written in various programming languages using algorithms to control the process and output of a computer. The programs must be converted into low level computer language, machine code which can be understood by a computer.
The machine language can run and execute very fast as the code will be executed directly by a computer. However, machine code cannot be usable by humans directly as it will be in binary code.
The assembly language converts the instructions represented in machine code with alphanumeric symbols, known as mnemonics in order to make it easier to work with them. The Assembler that is used to convert the assembly language into machine code for computer to execute the instructions written.
The high level languages are written in easily understandable format which is similar to human languages. The high level languages are platform independent that can be executed on different type of machines. The high level program, which is also known as source program is translated into machine code using compiler or interpreter.
A compiler is a system software program that transforms high-level source code into a low-level machine language. The process of converting high-level into machine code is known as compilation. An interpreter is a program that reads and execute source code statement one at a time and then continues with the next statement.