To introduce something is to bring something new to a situation. If your roommate never cleans up after herself, you might try to introduce some new housekeeping policies. Or, introduce yourself to someone who is looking for a new roommate.
Introduce has a number of related meanings. It’s often used when bringing people together for the first time, as when a talk show host introduces a guest to the audience, or when you introduce a new girlfriend or boyfriend to your parents. Introduce comes from the prefix intro-, meaning "into," and the Latin word ducere, meaning "lead" — just as you may have to lead (or drag) your new sweetheart in to meet your parents.