If you want to mirror your Android device screen on your desktop computer, then you do not need a huge or commercial software. All you need is an open-source tool called scrcpy for mirroring the screen and also controlling your Android device from the desktop computer. It works with all Android devices running on Android 5.0 (Lollipop) and above. It is available for Windows, macOS, and many distributions of Linux.
As far as the package for Windows is concerned, it comes with all the necessary tools including the ADB program that is used to interface with the Android devices through USB debugging. In order to make it work the target Android device must have developer options enabled (which can be done by quickly tapping 7 times on the Android build number in the Android settings) and then enabling USB debugging from within the developer options.
Once these requirements are met, you can just connect your Android device to your computer through a USB data cable and then launch scrcpy.exe. You will find out that scrcpy is actually a console program. If you do not want to see the console window, the developers have provides scrcpy-noconsole.exe which does not show any console window. The very first time, you may have to allow the permission for USB debugging prompt on your Android screen.
If everything goes right, a window will open up and your Android screen will be mirrored there. You can use your mouse, touchpad or keyboard to control the Android screen from this window. But this is not all this scrcpy tool can do. Using the proper command line arguments, you can switch to the fullscreen mode, record the Android screen to an MP4 or MKV video file, and more.
For example, if you want to run it in the fullscreen mode then you can give the command scrcpy -f and if you want to record the Android screen to a video file then you can use the command scrcpy -r video.mp4. You can see the full set of arguments and options by giving the command scrcpy –help.
Apart from the command line arguments, it also supports shortcut keys or hotkeys. For example, you can toggle the fullscreen mode using Alt+f hotkey, change the device volume using Alt+↑ and Alt+↓ hotkeys, rotate the device screen using Alt+r etc. By default it works with only left Alt key on your keyboard.
Compared to some other bulky tools that we have used in the past, scrcpy is very lightweight and works without installing anything on your system. It is fully portable and offers tons of options for controlling and mirroring your Android device screen.
You can download scrcpy from https://github.com/Genymobile/scrcpy.