Standard Terminal Arrival Route
A Standard Terminal Arrival Route or Standard Terminal Arrival (STAR) is a published procedure followed by aircraft on an IFR flight plan just before reaching a destination airport. A STAR usually covers the phase of a flight that lies between the top of descent from cruise or en-route flight and the final approach to a runway for landing. (wikipedia)
Let's try some scenario. You are in a plane, destination KSFO, coming from the east. You will contact ATC, and the controller will tell you what SID to use and what runway to land on. This time we need to make use of a "Modesto Three Arrival" and runway 28R. On a STAR chart (we use this one) we can see what waypoints we need to follow during our approach (and descend). Namely:
OAL MOD CEDES MEHTA DUMBA
Now we turn our plane, directing to OAL (Coaldale). You can use the route manager to show the heading you need to follow. Every time we pass a waypoint we will change our heading (if needed) to the next one. So after we've passed OAL we direct our plane to MOD. And so on, till we intercept the ILS localizer for runway 28R.