> For the complete documentation index, see [llms.txt](https://strctr.gitbook.io/programming/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://strctr.gitbook.io/programming/01-languages/javascript/01-language/a-core/a1-javascript-execution/01-execution-context.md).

# 01. Execution Context

When JS code executes, it always happens within certain *execution context*. For each of types of executable code, there’s an execution context. There are 4 types of executable code in JS:

* **Global code**,
  * Content of `<script />` elements
  * Non-module code
* **Module code**,
* * Content of `<script type="module" />`
  * Module code
* **Function code**,
  * Content of event attributes (e.g. `<p onclick="...">`)
  * Anything that’s executed directly within a function,
* **Eval code**.
  * Text that’s supplied to a built-in `eval` function is parsed as *Eval code*

As you can see, execution contexts can logically form a stack:

1. First there might be Global code or Module code with its own execution context;
2. That code might call a function, with its own execution context;
3. That function could call another function, and so on and so forth.
4. Even if function is calling itself recursively, a new execution context is being entered with every invocation.


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