If not, then what's the difference between the beliefs of the 2.
Most Helpful Guy
Yes Catholicism is a denomination of Christianity similar to Sunni or Shiite being different forms of Islam. There are some Muslims that don't consider Sufi to be true Islam which is similar to some protestant Christians not thinking Catholics are true Christians. I think I heard once that Christianity has over 20,000 different denominations mostly falling under the branches of Protestantism since they don't have a centralized system like in Catholicism. Protestants and Catholics, along with the Eastern Orthodox traditions, all fall under the umbrella of Christianity though. There is a movement particularly in the United States that tries to discredit Catholics and say they aren't real Christians. They give all kinds of 'reasons' like they worship Mary and the Pope. It's all a bunch of bullshit when it comes down to it because something all Christians have in common is that they worship God in the trinity (father, son, holy spirit/ghost). Most of the basics are pretty similar even if they worship differently or with different traditions.
Keep in mind I'm not Christian so I hope I represented everyone properly. Feel free to correct any aspect that I have incorrect.0