Looks like Papa3 gave a pretty good description of the tasks.
So I will try for an overly simplifed version.

There are currently 3 task types.

1. Assigned Task,

Fly to all the assigned points in order and return.

2. Modified Assigned task.

Fly to as many of the assigned points as you want to (in order).
If you complete them all you may add additional points of your
choosing.
A minimum time on course will be assigned, if you come back under this
minimum time, your time on course will be scored as the minimum time.

3. Turn Area Task

Same as the Assigned task however the turn points may have a very
large Radius.
A minimum time on course will be assigned, if you come back under this
minimum time, your time on course will be scored as the minimum time.


Of course this doesn’t talk about scoring or strategy.

Brian