Patent, in short, is who declared something, or a certain technology, type, style, etc. First and prove that you are the inventor or owner, you will get the patent right of the item or technology, that is, others can't use it, so I have to pay.
In this way, it is easy to understand why Apple needs to give money to Nokia.
Think about it. Nokia has been making mobile phones for so many years. How many technologies, styles and types are there on a mobile phone? Anyway, how many patents Nokia has?
As far as the development of mobile phone technology is concerned, Apple is far from using Nokia's technology, so it is normal to give money to Nokia.
The more patents, the faster the money will come.