POKEMONS
The concept of the Pokémon universe, in both the video games and the general fictional world of Pokémon, stems from the hobby of insect collecting, a popular pastime. Players are designated as Pokémon Trainers and have three general goals: to complete the regional Pokédex by collecting all of the available Pokémon species found in the fictional region where a game takes place, to complete the national Pokédex by transferring Pokémon from other regions, and to train a team of powerful Pokémon from those they have caught to compete against teams owned by other Trainers so they may eventually win the Pokémon League and become the regional Champion.
Mew vs Mewtwo
Mewtwo is Mew's bigger and more powerful clone. Mewtwo has been through more trauma than its original. Mew has a better variety of attacks, but Mewtwo's overall Pokédex stats are better. Though Mewtwo has raw power, it does not have the centuries of experience in battle that Mew possesses. Mew also has more willpower to survive, while Mewtwo attacked out of anger.
Mew
At first glance, Mew is a small, adorable Pokémon who loves to play with both trainers and other creatures. This tiny creature is a fan favorite among children who love its playful nature. Though Mew may charm you with its large eyes and cat-like aloofness, it's easy to misjudge this Psychic-type Pokémon. Mew is an ancient Pokémon and has witnessed the evolution of its species over time and Mew enjoys observing on the sidelines.
Mewtwo
Though Mewtwo is Mew's clone, it is not the evolved form of Mew. The Laboratory created clone Mewtwo is often considered stronger, but still uses Mega Evolution forms. Mewtwo was seen as a boastful, destructive powerhouse seeking revenge.