Ok, it's a little tricky to explain, not to mention I suck at forum examples lol
For the While loops, it will basically keep looping until whatever condition is in the event along with 'while' doesn't happen anymore.
player overlaps obstacle
(or 0.1 if you wanna be super accurate)
The loop moves the player up a pixel each time through the loop until the player is no longer overlapping the obstacle.
The other loops like 'For' are a little more interesting and I -think- they require the use of sub-events, although are harder for me to use. Basically instead of the loop repeating until a condition is met, the loop runs a predeterminded amount of times.
1 For "move" = 1 to 10
2 --(subevent)When Right Arrow is down - player.X = player.x + 1
The result is what looks like the player moving to the right in increments of 10 pixels when in fact it's moving one pixel at a time
That's all I learned from playing around with the loops in construct, I'm still working it all out though lol!
Hope that was helpful