What is the difference between Time and "Moving Time" for Activity=Skiing?

The first three times i went skiing, "Moving time" was about double of "Time" and so i thought maybe "Moving Time" included time on the lift, since i would expect that about half of time was on the lift (and only time in descent actually counts as activity time). However, the last 4 times i went skiing, "Time" and "Moving Time" were almost identical, just a few minutes different.

Can somebody tell me the difference between "Time" and "Moving Time"? What is each supposed to measure?

And, does anybody have any idea why on some skiing days they would be identical and on others they would be quite different (double/half).

Thanks!