As opposed to the best Windows video editing software, online video editors are not dependent on your operating system. So you can edit on a Mac, a PC, a tablet (Android or iPad) or even a Chromebook (a cheap laptop designed mostly for web surfing).
However you need a good internet connection to upload your files to the cloud but once that's done you can edit at your convenience - there's no need for lots of RAM or processing power on your machine. It all happens online - the service provides all the tools and effects you need.