Good post from Hackaday on how lasers actually work - seems to cover all the points with good explanations (And some nice graphics to go with them!), although may be a little in depth for some. :)
Also a good video in the comments that'd be worth a watch. :D
How Lasers Actually Work | Hackaday
Also a good video in the comments that'd be worth a watch. :D
How Lasers Actually Work | Hackaday