Android, and its variants, is the major operating system used by mobile devices of all types, with iOS being the next major one. If a tablet uses android, that gives it access to a huge amount of content, apps, games, videos, ebooks and more, from stores such as Google Play. Running on Android can therefore significantly increase the amount of content that it available.
The Tagital T7K is an Android tablet, running 4.4.2 KitKat out of the box, which is now quite an old version of Android, although it’s one that does still see quite a lot of use on devices. This gives the tablet access to a lot of content, although a parent will need to use the parental controls to configure just what their child has access to personally.