There are three components in the taxonomy proposed by Benjamin Bloom et al.

affective

The way people react emotionally, their ability to feel another living things pain or joy. see also affective filter Affective objectives typically target the awareness and growth in attitudes, emotion, and feelings.

psychomotor

The ability to physically manipulate a tool or instrument like a hand or a hammer. Psychomotor objectives usually focus on change and/or development in behaviour and/or skills.

cognitive

This is the ability 'to think things through'. Cognitive objectives revolve around knowledge and comprehension of any given topic.

There are six levels in the taxonomy, moving through the lowest order processes to the highest:

Name of level	Description
Knowledge	Exhibit memory of previously-learned materials by recalling facts, terms, basic concepts and answers
Comprehension	Demonstrate understanding of facts and ideas by organizing, comparing, translating, interpreting, giving descriptions, and stating main ideas
Application	Solve problems to new situations by applying acquired knowledge, facts, techniques and rules in a different way
Analysis	Examine and break information into parts by identifying motives or causes. Make inferences and find evidence to support generalizations
Synthesis	Compile information together in a different way by combining elements in a new pattern or proposing alternative solutions
Evaluation	Present and defend opinions by making judgments about information, validity of ideas or quality of work based on a set of criteria