1# Update App<a name="EN-US_TOPIC_0000001148414479"></a> 2 3- [Introduction](#section182mcpsimp) 4- [Directory Structure](#section190mcpsimp) 5- [Description](#section198mcpsimp) 6- [Repositories Involved](#section206mcpsimp) 7 8## Introduction<a name="section182mcpsimp"></a> 9 10The update app runs on the OHOS and provides an interactive GUI for users to perform version updates. 11 12It provides the following functions: 13 141. Check for available update packages and display the check result. 15 162. Download the update package and display the download progress. 17 183. Trigger an update. 19 204. Obtain the version information after a version update. 21 22## Directory Structure<a name="section190mcpsimp"></a> 23 24``` 25base/update/app # Update app code repository 26├── entry # Access to the update app code 27│ └── src # Update app code 28└── gradle # Configuration files 29 └── wrapper # Gradle configuration files 30``` 31 32## Description<a name="section198mcpsimp"></a> 33 34The update app is implemented by using JavaScript, and the service logic is implemented by using C++. The JavaScript app interacts with the service logic through NAPI. 35 36For details about the NAPI implementation, see the following: 37 38base/update/updateservice/client 39 40## Repositories Involved<a name="section206mcpsimp"></a> 41 42Update subsystem 43 44**update\_app** 45 46[update\_updateservice](https://gitee.com/openharmony/update_updateservice) 47 48