Javascript
Javascript is a dynamic, single threaded ansychronous programming language.
Asyncrhonous programming can be described as allowing a program to allow several things to happen at the same time. Javascript can start and action, continue to run the program and then run the action once it is finished yielding a retrun. This differs from other programming languages which may stop until that action is finished until moving forward.
This can be seen in a classic setTimeout() example as a function’s return is provided once the time has run or even a request awaiting a response where the response is return after some time. This response happening after a subsequent console.log immediately following.

Though Javascript is said to execute asynchronously — the event loop is allowing you to queue up an action that won’t return until that action has finished executing.