An interpreter is software that executes code directly, often statement by statement, instead of first translating the whole program into a separate executable. Languages and environments such as BASIC prompts, shell interpreters, and scripting runtimes use this model to give immediate feedback and make experimentation easy.
In cyber security, interpreters matter because they sit close to raw execution. That makes them useful for defenders, who rely on scripts, consoles, and automation to inspect systems and respond quickly. It also makes them attractive to attackers, who may abuse an interpreter to run commands, launch payloads, or execute fileless code without dropping a traditional binary. When a system boots into or exposes an interpreter by default, the trust boundary becomes important: whoever can feed input to that interpreter can often direct the machine’s behavior.