1# Process Model (Stage Model) 2 3 4The OpenHarmony process model is shown below. 5 6 7- All UIAbility, ServiceExtensionAbility, and DataShareExtensionAbility components of an application (with the same bundle name) run in an independent process, which is **Main process** in green in the figure. 8 9- The ExtensionAbility components of the same type (except ServiceExtensionAbility and DataShareExtensionAbility) of an application (with the same bundle name) run in an independent process, which is **FormExtensionAbility process**, **InputMethodExtensionAbility process**, and other **ExtensionAbility process** in blue in the figure. 10 11- WebView has an independent rendering process, which is **Render process** in yellow in the figure. 12 13 **Figure 1** Process model 14 15 16> NOTE 17> 18> - You can create ServiceExtensionAbility and DataShareExtensionAbility only for system applications. 19> - To view information about all running processes, run the **hdc shell** command to enter the shell CLI of the device, and run the **ps -ef** command. 20 21A system application can apply for multi-process permissions (as shown in the following figure) and configure a custom process for an HAP. UIAbility, DataShareExtensionAbility, and ServiceExtensionAbility in the HAP run in the custom process. Different HAPs run in different processes by configuring different process names. 22 23**Figure 2** Multi-process 24 25 26 27OpenHarmony provides two inter-process communication (IPC) mechanisms. 28 29 30- [Common Events](common-event-overview.md): This mechanism is used in one-to-many communication scenarios. Multiple subscribers may receive events at the same time. 31 32- [Background Services](background-services.md): This mechanism is implemented through [ServiceExtensionAbility](serviceextensionability.md). 33
