# JavaScript ep-1

Everything in JS happen inside execution context.

Imagine a closed container inside which JS runs.

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1734359870792/c18372ee-fa58-4be3-97b3-facff6b3b369.jpeg align="center")

The first compnet is knowns as **variable component/memory component** and the second component is known as **code component.**

Memory component:It store all variable and function in key value pair.

Eg: a=undefined

const name=function getName()

{

}

Javascript is a **synchronous,single thread language**  
**what does it mean?**

Synchronous:One command at a time.

Single threaded:In a specific synchronous order.