Projection (relational algebra)

Projections in relational algebra are like asking a question and getting an answer. For example, if you had a table of pets and wanted to know all the different types of pets, you would ask the table a "projection" question. This would return a list of all the different types of pets in the table - like dogs, cats, frogs, etc. It's like a way of looking at the table and getting a list of the different possibilities.