Cocomo Intermediate model

The cocomo model is just a method to estimate cost of making a software and the amount of resources i.e. programmers, computers, etc needed right? Do correct me if my definition is wrong or partial please.

I can't understand the intermediate model, it uses 15 method to improve the accuracy, that's what google told me, but seems way too complex to understand.

Can someone please explain the cocomo model, and the intermediate variation of it please.