A Summary of Roblox: Roblox is a website where you you can make games inside of it. It sounds confusing, but on the main part of Roblox, you can make your account, find games to play, customize your avatar, etc. The playing games part of the site is made by other people that you can play- no download, and all free. Its compatible on a lot of devices. Roblox is maybe a bit like the game platform Steam. Except you have to pay and download the games on steam.
Roblox logo, found in the public domain in Bing images.