Familiarization is the noun: the process of learning about something until you understand it, or of walking someone else through it until they do. A new worker may have a familiarization day; a company may run a familiarization tour for visitors; a pilot may need familiarization with a new aircraft before flying it. It is a workplace and training word, a little stiff for home — there you would more often say getting to know or learning about. The British spelling is often familiarisation, with an s, matching familiarise. The thing itself does not change: it is still the settling-in, the “now I see how this works” stage, not a one-time flash of understanding.

熟悉過程；熟悉訓練