What is…?   
Fasting:Eating one full meal, as well as two smaller meals that together are not equal to a full meal.

Abstinence:  Not eating meat (Chicken, beef, pork, lamb, veal)

Who has to…?
Fast: Catholics from age 18 through 59
Abstain:  All Catholics from age 14 onwards

When do I…?
Fast & Abstain: Ash Wednesday & Good Friday
Abstain (only):  All Fridays during Lent