After entering your credentials and installing the official AirDroid app on your Android device (also available on Uptodown), you can access different sections of the program. You can send all kinds of files and even create folders from Windows which will synchronize remotely. You can also access your entire text message history if it has been stored in the call log or contacts list.
One of the most interesting options is the AirMirror feature which lets you see a mirror image of your Android device on the screen and even lets you use your mouse to interact with it. This, along with the practicality of receiving all your notifications on the Windows desktop notification bar, makes AirDroid a really useful tool.
Some advanced options are not available in the free version, such as a monthly transfer limit of 200MB.