Procedural knowledge, also known as know-how, is the knowledge exercised in the performance of some task. Unlike descriptive knowledge, which involves knowledge of specific propositions, that is, facts that can be expressed using declarative sentences, procedural knowledge involves one's ability to do something. A person does not need to verbally articulate their procedural knowledge for it to count as knowledge, since procedural knowledge requires only knowing how to correctly perform an action or exercise a skill.