1# System Modules<a name="EN-US_TOPIC_0000001199722621"></a> 2 3- [SAMGR](#section105874301910) 4- [DFX](#section20064420420) 5 6System modules, such as the system ability manager \(SAMGR\) and DFX subsystem, provide basic capabilities for upper-layer applications. During board-level system porting, you can directly select the system modules as required without any adaptation. 7 8## SAMGR<a name="section105874301910"></a> 9 10**Introduction** 11 12This service-oriented framework enables you to develop services, features, and external APIs, and implement multi-service process sharing and service invocation for inter-process communication \(IPC\). 13 14> **NOTICE:** 15>This module must be used during board-level system porting. Otherwise, other service modules cannot run properly. 16 17For details about how to use SAMGR, see [samgr\_lite](https://gitee.com/openharmony/distributedschedule_samgr_lite/blob/master/README.md). 18 19## DFX<a name="section20064420420"></a> 20 21**Introduction** 22 23The design for X \(DFX\) subsystem mainly includes design for reliability \(DFR\) and design for testability \(DFT\), providing code maintenance and testing. 24 25For details about how to use the DFX subsystem, see [DFX](../subsystems/subsys-dfx-overview.md). 26 27
