Syntax Parser: A Program that reads and determines what it does and if the grammar is valid.
Lexical Environment: where something sits physically in the code you write.
Execution Contexts: A wrapper to help the code that is running.
Callbacks: A callback is a function passed as an argument to another function. This technique allows a function to call another function. A callback function can run after another function has finished.
Coercion: Converting a value from one type to another