That is because the GPS also has information from the onboard compass and thus knows about the heading as well as the track over ground. It also has airspeed information in addition to GPS derived speed over ground.

-- Chris.

Thank you very much.
On airliners the GPS gives all the time the actual winds ( if you ask for it.)

Is it possible that  you enter an TOT (time over target)  and Sky-demon tells me how fast i have to fly to make that TOT during an Navigation trip?

To ensure the forecast is populated as high as 10,000 feet, you'll need to ensure the route you plan goes that high and covers the time at which you'll be flying. Then the wind instrument should display a value once you're flying. As mentioned above, though, it's a forecast value and the actual winds aloft might be doing something else.

Rico, without heading information there can be no display of actual winds aloft. What you see displayed is interpolated data from forecast winds aloft. No forecast value, no display.

-- Chris.

While climbing to 10000 ft, I remembered that I could see the actual wind in right hand corner.
The last few flights i saw that the windindication disapeared when I was climbing through 2600 ft.and was replaced by a cross.
q. Is this the actual wind calculated by the GPS.
     do I need to insert a route to get the actual wind, is this correct?

I like to use this windinfo to pass this on to the sky-divers i fly.