Interpreter

An interpreter executes source code or an intermediate representation without first producing a standalone native executable. It may translate code incrementally or execute it through another representation.

Abstract syntax tree: A tree representation of a program's syntactic structure, with operators and statements as nodes. Many interpreters walk this structure directly to execute parsed programs.
Compiler: A program that translates source code into another representation, often machine code, before execution. Unlike an interpreter, a compiler can produce a standalone executable before the program runs.
Read–eval–print loop: An interactive programming environment that repeatedly reads, evaluates, and prints expressions. It exposes an interpreter's evaluation cycle directly to interactive users.
Ahead-of-time compilation: Translation of a program into machine code before its execution begins. It is the common alternative to interpreting code at runtime.
Portability: The ability of software to run across different computing environments with limited modification. An interpreter can provide similar language behavior on each platform where its runtime exists.
Bytecode: A compact instruction set designed for execution by software or a virtual machine. Interpreters often execute bytecode instead of repeatedly processing source text.
Programming language: A formal language for expressing instructions and computations that can be processed by a computer. An interpreter implements the rules of a particular programming language.
Shell script: A text file containing commands executed by a command-line shell. Shells commonly interpret scripts one command at a time.
Transpiler: A program that translates source code from one programming language into another. A transpiler transforms code rather than directly executing it.
Interactive computing: Computing in which users give commands and receive responses during execution. Interpreters can evaluate fragments immediately, supporting exploratory workflows.

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