A combo long/lat is a waypoint (single location). If you entered that data you will have a waypoint displayed on the Chart View. It would not be a Trail or Track.
A Track is a line that is created on the Chart View as you move. It consists of Track Points. Trail is what Lowrance calls a Track.
This is Google Earth image of a Track from the ramp to another location on the lake. The Track was saved by me with a Humminbird unit and just viewed with Google Earth. It is a result of what I described in the second paragraph above.