> For the complete documentation index, see [llms.txt](https://www.ngxs.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.ngxs.io/v3.4/concepts/intro.md).

# Introduction

There are 4 major concepts to NGXS:

* Store: Global state container, action dispatcher and selector
* Actions: Class describing the action to take and its associated metadata
* State: Class definition of the state
* Selects: State slice selectors

These concepts create a circular control flow traveling from a component dispatching an action, to a store reacting to the action, back to the component through a state select.

![](https://342744504-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-L9CoGJCq3UCfKJ7RCUg%2F-LVrR_Jobt3NVt61AhlH%2F-LVrRb1WdI1nngz9VmFm%2Fdiagram.png?generation=1547118480096027\&alt=media)