Segment is a routing platform for your customer data (what they call a “customer data platform”). Engineering and data teams use Segment to:
Fire events whenever their customers take actions in the product (e.g. page viewed)
Move data between standard sources, like Mixpanel to Salesforce
Manage customer profiles via a single “persona” and transform data on the fly
If these bullet points seem to have nothing to do with each other, you’re onto something - Segment is really hard to explain because it does a lot of things all together, and until you understand all of them separately, it won’t make sense. And that’s why, in general, very few non-developers do actually understand what Segment does.