A total of 47.5 wins the over at 48+ combined points and the under at 47 or fewer. Whole-number totals can push. Totals respond to different information than spreads - pace, weather, and offensive scheme move totals; team strength moves spreads - which is why total and spread positions in the same game can be combined into correlated structures.
Totals are market key totals, with the point value on each outcome. Team totals and alternate totals appear as separate keys in the catalog (/v1/meta/markets). Totals move fast on lineup and weather news close to kickoff - the movers view ranks the day's biggest shifts.