> For the complete documentation index, see [llms.txt](https://edgex-api-advantech.gitbook.io/edgex-api-doc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://edgex-api-advantech.gitbook.io/edgex-api-doc/advanteched-services-apis/edgex-service-layers.md).

# EdgeX Service Layers

EdgeX Foundry is a microservice-based API framework. It provides southbound device connectivity and northbound application connectivity.

## **Content**

* Architecture
* Southbound microservices
* Northbound microservice

## Architecture

![](https://1210863923-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-Ldahy90A1eekcr5A2U8%2F-LdcTh21agYTbsgujiEB%2F-LdcToNhb-lZDISL_ckD%2Fimage.png?alt=media\&token=685f4fde-036e-403a-839f-ffe72df79af6)

Device Services (DS) are the edge connectors interacting with the devices or IoT objects. Device services may service one or a number of devices, including sensors, actuators, and so forth.