I generally try to have a vegetarian diet in the week and only eat meat on the weekends... But generally I avoid any meat such as chicken, fish, beef, etc... I only try to eat vegetables, beans, pasta, eggs, dairy products... I just avoid the actual meat itself.
Vegan diets are a whole other story though... They generally avoid dairy, eggs, cheese, butter, any meat, anything from any animal... Some extremes avoid clothing from animals (wool, leather, etc...).
Vegetarian diets are quite easy, vegan ones are a bit more difficult.