A schema is something that data processing platforms such as Google Analytics apply to the raw hit data coming in from the data source (usually a website). The most visible aspect of Google Analytics’ schema is how it groups, or stitches, the arbitrary, hit-level data coming in from the website into discrete sessions, and these are actually grouped under yet another aggregate bucket: users.
But you already know this. You’re looking at metrics like Sessions, Bounce Rate, Conversion Rate, and you’re using them or variations of them as KPIs in your dashboards and whatnot.
