I've just been looking at the wikipedia entry for Xi Jinping and the word used for the position he will be taken on Wikipedia is incumbent "paramount leader" with paramount leader pointing to this Wikipedia article. There is also a Chinese version of that page which translates paramount leader as 黨和國家最高領導人.
If I look at the very bottom of the 党和国家领导人 it also has 习近平（最高领导人）.
I'm hoping someone can help me, and forgive me if the answer is on the linked pages (my reading is too slow).
Here are my questions:
党和国家领导人 - Is this singular or plural or both?
What is the difference between 最高领导人 and 主要领导人之一?