Cookie is a small piece of data stored in a browser to remember information about a user, session, or preference.
It matters because most visitors do not convert on the first visit. Retargeting terminology helps teams create thoughtful follow-up sequences, avoid wasted impressions, and respect audience exclusions and privacy expectations.
Example
A site might store a cookie that remembers a visitor’s language selection for the next visit. An advertising cookie, where enabled, can store an identifier used by a separate tracking system. The cookie itself does not display an ad or send a follow-up message.