We don't delivery physical products, instead you'll receive a game "key" (a unique to you sequence of numbers and letters) that acts as a sort of password to allow you to download, install and play a game.
Game keys are unique to you and can be redeemed only once, mainly they will work on the Steam platform, unless otherwise stated in the game’s System Requirements.
If you don't already have it installed on your computer please refer to this article for details of how to install the Steam client.
You will need to login to Steam using a Steam account, if you don't already have one please refer to this article for details of how to create a steam account.
After you have logged into your Steam account you use the keys you have received from Bundle Stars to add the games to your Steam library so that you can download, install and play them on your computer- please refer to this article for more details of this process.