Everything in JS happen inside execution context.
Imagine a closed container inside which JS runs.
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.