In the latest versions of SharePoint and SharePoint Online, you need to use PowerApps if you want to customize SharePoint list forms. PowerApps is an online app-building platform. You can create independent native apps in PowerApps connected to your own data sources. These apps can easily run on almost any device and platform, like Windows, iOS, Android, mobile devices, iPad etc.
In .NET, if you need to show a message to the user, you can use the MessageBox class. In HTML and JavaScript, you can use Alert function. Similaraly, you need something to show a message, confirmation box, or a dialog box in PowerApps. There is no function or control available out of box here. So, in this video, we will see how to show a message box or dialog box in PowerApps.