What is Other in IPhone storage?

My IPhone 6s is almost full, and when I look to see what is on it, it says over half is full of "Other." What is it? It's not apps or music or photos. I looked online and it said to clear internet browser history and that did nothing. Could it be one of my apps? I just want it gone.

It mostly has cache and data used by your apps like FB, WhatsApp etc.

By the passage of time apps increase and contain all the data.