WebView2 SDK is a package containing mandatory components for the development of hybrid applications, meaning programs that use web resources and low-level utilities and resources for Windows development — e.g. the C/C++ programming language, Windows APIs, libraries, frameworks, etc.
This component is vital for developing Electron-like apps with the added benefits of increased security, scalability, flexibility (using Windows frameworks for developing an application's backend and Edge's Chromium-powered capabilities to adjust the front-end), and extensive application support — the Microsoft's community's support, the extensive documentation, the walkthrough guides and app-building tutorials, plus the added benefits of the samples.
Also, on top of all the resources, you can find online for easily getting started with the hybrid-app development, you can also analyze, build, compile, or debug a sample project from Microsoft Edge's GitHub — a web browser built using the Microsoft Edge WebView2 control.
All things considered, you should try this development toolkit (Microsoft Edge WebView2 Runtime) if you are curious about WebView2's capabilities (it favors rapid development, code resharing, web-component addition, etc.), extensive support (even on older Windows platforms — it is compatible with Win7 and even supported on Windows Server R8), and compatibility traits (it is available on the following programming environments — Win32 C/C++ (GA), .NET Framework 4.6.2 or later, .NET Core 3.1 or later, .NET 5, and WinUI 3.0 (Preview)).