Experience
Part of speech: noun
Definition: Event(s) of which one is cognizant. Activity which one has performed. Collection of events and/or activities from which an individual or group may gather knowledge, opinions, and skills. The knowledge thus gathered.
Part of speech: verb
Definition: To observe certain events; undergo a certain feeling or process; or perform certain actions that may alter one or contribute to one's knowledge, opinions, or skills.
Expertise
Part of speech: noun
Definition: great skill or knowledge in a particular field or hobbyadvice, or opinion, of an expert