The word "记住" is formed by combining two independent characters, each contributing its core meaning to create a new, composite idea. The first character, "记" (jì), carries the fundamental concept of recording or retaining in the mind, meaning "to remember" or "to note". The second character, "住" (zhù), literally means "to live" or "to stay", but here it functions as a resultative complement, adding the sense of something being fixed, settled, or held fast. Therefore, the formation conceptually fuses "to record/to remember" with "to make it stay", resulting in the combined meaning of "to remember firmly" or "to commit to memory".