Venom is a movie that is coming into theaters very soon. It stars Tom Hardy as the main title character, Venom. He plays Eddie Brock and Venom. He must be both characters in order to possess and use the superheroic powers. MCU stands for Marvel Comic Universe. This includes the characters from the Marvel Comics.
MCU also stands for Marvel Cinematic Universe. Venom is part of the MCU. That is, he is part of the Marvel Comic Universe based on the role he plays. However, Spiderman is not part of the Marvel Cinematic Universe since he does not play a role in this movie. Yet, he is part of the Marvel Comic Universe and has been portrayed in previous movies.