What Is An Interpreter?

Interpreter   

          An interpreter is programme that translates a high-level programming language into machine language during the actual step-by-step execution of a programme. Translation and execution alternate for each statement encountered in the high-level language programme. In other words, an interpreter translate one instruction, and the control unit execute the resulting, machine language, the next instruction is translated, and the control unit execute the machine language instruction, and so on. If the programme is sun seven times a day, the programming language is reinterpreted seven times.
In case of a compiler, the whole source program is translated into an equivalent machine language programme. The object programme, thus obtained is permanently saved for future used and is used every time the programme is to be executed. So repeated compilation is not necessary for repeated execution of a programme. However, in case of an interpreter, no object programme is saved for future use because the translation and the execution processes alternate. The next time an instruction is used, it must once again be interpreted and translated into machine language. For example, during the repetitive processing of the instruction with in a loop, each instruction in a loop will have to be reinterpreted every time the loop is executed.

You must understand interpreter in different conditions and on different positions. In simple words interpreter is the person who orally translates from one language to another language. For example, if a head of state is speaking in United Nation's meeting then it is very obvious that many people would not understand his language. To translate his address so that all people can understand the interpreter are designated to do this job. They translate the language of the speaker in the desired language. There is another type of the interpreter I'm giving information about them below.

When a computer program is designed in some computer language like Java, C or C++ then computer needs to understand the instructions which are given in that language. So these instructions are translated by a program into a machine language that is also called the interpreter.

So there are basically 2 types of interpreter which I've mentioned. One is the real human beings who translate the language of the words in the other desired languages while on the other side the interpreter of computer works to convert some computer language in machine language. I hope this answer is sufficient for you to understand.