There are many reasons why people chose to become vegetarian and there are different types of vegetarianism. When done right, following a vegetarian diet can be part of a healthy lifestyle.
The different types:
Semi-Vegetarian: Will eat everything except red meat
LactoOvoPesco-Vegetarian: Will eat dairy, fish, and eggs, but no other animal sources.
LactoOvo-Vegetarian: Will eat dairy and eggs, but no fish or meat.
Lacto-Vegetarian: Will eat dairy but no eggs, fish or meat.
Vegan: Will eat only foods from plant sources.
How to be a healthy vegetarian:
Don't forget the basics. Vegetarians need variety and moderation like everyone else.