What is “the system” in iPhone storage and why does it take up 70% of my storage?

My iPhone has a whopping 16 GB of storage and it’s basically full. I’ve deleted basically all of my apps and I’m down to basically 12 but I still don’t have any space. I looked at my storage and counted it up and my actual apps only take up about 4.3 GB, but for some reason “the system” storage takes up 11.12 GB. I don’t even have enough storage to update my phone and I’m not sure what “the system” is or why it is taking up all this space. Is there anyway to reduce this number?