Here is a brief overview of the types of vegetarian lifestyles that are practiced
Ovo-Lacto
Based on eating grains, vegetables, fruits, legumes, nuts and seeds, eggs and dairy products.
Lacto-Vegetarian
Similar to Ovo lacto but eggs are not eaten.
Ovo-vegetarians
Similar to Ovo lacto, eggs are eaten but dairy is not.
Vegans
Based on grains, vegetables, fruits, legumes, nuts and seeds but eliminates all meat, eggs and dairy.
Semi-vegetarians
This refers to people who eat predominantly vegetarian but will occasionaly eat fish, poultry or meat or they may eat mostly vegetarian but will eat fish, there is no real exact description for this term,