A list is a static collection of people’s email addresses and/or phone numbers grouped under an identifiable label. They contain anyone who has subscribed to the list and will only grow or shrink as people either subscribe or unsubscribe. As a general best practice, we recommend having a single main list that contains all of your active profiles who consented to receive marketing from your brand.
Meanwhile, segments are defined by a set of conditions rather than a fixed list of people. A segment will grow as new people meet the conditions and shrink as people no longer meet them, updating automatically and in-real time.
For more details, head to our article, The Difference Between Lists and Segments.
You can use segments to level up your campaign strategy, trigger flows, target forms, sync with social media, or analyze your marketing performance. Need ideas for types of segments to build? Check out this article on creating customer engagement tiers.