Hey there @Ollie0226. If you are wanting to take a look into a further breakdown of your data usage and where this may have been used up, I recommend checking out your mobiles "Data" settings on your device. You can find the steps for your device via our device guide landing page.
It's a file sharing program for movies, music and such. By default it will share everything you have downloaded with other users and this can result in large amounts of data being downloaded and uploaded especially if its running in the background without your knowledge. Best to terminate the process and remove the program if you have no idea why it is on your device.