Fairly similar, different origins. Butter Chicken originated in India, while Tikka Masala originated in Britain. Other than that, Butter Chicken's curry/gravy/sauce is blended up and smooth. There's also more butter involved.
Someone correct me if I'm wrong, but I believe that butter chicken is also known as murgh makhani. murgh makhani is different than Masada because the gravy or sauce is made different or has some different ingredients.