# Context and Environment

### Execution Context:

* When java script engine sees the brackets, creates its own execution context inside the call stack, after the execution it will popes out the call stack. 
* Any time running the java scrip code, it will be a part of execution context.

![Execution Context Operation](/files/-LiJdKqGwOWoXSiLMxmV)

####    Global Execution context:

* when ever we run the java script code, it creates a Global execution context that gives global object 'window' and 'this' and this === window.
* After the global execution context is created, functional execution context will be created.

### Lexical Environment:

* Lexical is compile time.
* Makes to know where the code is written.
* Every function creates a new lexical environment.
* Execution context says which lexical environment is currently running.

####     Lexical scope: (definition)

    Lexical scope (available data + variables, where the function was defined) determines the available                                                     variables.

####    Dynamic scope: (execution)

    Where the function is called.

![Execution Context](/files/-LkRXWyYqTIFlWgCs8uM)


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