Why is there 10GB of space on my iPhone 5s

I just recently recieved my iPhone 5s and synced it with the backup from my old iPhone 5 like i always have with previous iphones. Except this time there is over 10GB of 'Other' space on my new iPhone 5s. This 'Other' space was not on my iPhone 5. I would really like to know what all this 'Other' stuff is because 10GB is a lot of room i could be using!