A calendar date defines the service available on any given day. Use this in conjunction with trips to know if that trip operates on a given day.
A departure represent a bus approaching a given stop. Results include real-time departure time, route information, and vehicle location regarding the bus.
A route is exactly what it sounds like. Keep in mind that some routes maybe split up. (e.g. GREEN, GREENHOPPER, GREEN EVENING, GREEN WEEKEND, GREENHOPPER WEEKEND, etc.)
A shape is a list of geographic points that define the actual shape of the trip on a map. Shapes are not route specific, but trip specific as trips of a particular route may vary. Also, this is does NOT define the stops a trip makes, just points for mapping (check out GetStopTimesByTrip).
A stop point is a specific location where our vehicles will board or alight passengers. Results include geographic information.
A stop is a collection of one or more stop points in a logical or geographic grouping.
A stop time represents a scheduled arrival and departure time for a trip at a specific stop.
A trip is an individual run of a route at a specific time. While multiple trips may follow the same stop pattern, a trip is a single instance of that pattern.
If two trips have the same block_id, that indicates that these trips will be operated by the same vehicle.
