Every JS developer should know these concepts.. Syntax Parsers, lexical Enviroments and Execution context


Syntax parsers
 A program that ready your code and determines what it does and if its grammer is valid. Your code is not magic. Someone else wrote a program to translate it for the computer..

Lexical Enviroment 
Where something sits physically in the code you write..
lexical meand having to do with words or grammer. A lexical environment exists in programming languages in which where you write something is important..

Execution Context 
A wrapper to help manage the code that is running..
There are lots of lexical environments. Which one is currently running is managed via execution contexts. It can contain things beyond what you are written in your code.

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