A: Your 2-year-old might be aggressive, but isn't capable of being a bully. A bully intentionally picks out smaller, more vulnerable children to harass and humiliate. Your 2-year-old's brain simply isn't capable of doing that.
But aggression IS something that's common in toddlers. Don't label your child as a "bully" -- help him to learn about how to play well with others. These social skills are among the most advanced skills the human brain gains, and aren't fully formed until adulthood. So take heart! This is an ongoing learning process.
This is a great opportunity to get down on the kids' level to help them work out their differences. Help them take turns, use their words instead of their hands, and learn to identify their -- and others' -- feelings. You'll be helping him become a respectful, helpful, and patient child -- skills that will serve him well for a lifetime!