Function of <trkseg> ?

[PeteCresswell]

To better my understanding.... what's the intent of having separate <trkseg>'s instead of just having all the <trkpt>'s under one <trk>?

[Krein]

Tracksegs are different pieces of a single track.  We use them (as well as other GPX programs) to store 'breaks' in tracklogs (loss of signal or turning off).  Such tracks have breaks that is information that shouldn't be thrown away, but for example you still want to profile the whole track together, rather than in pieces.