Help understanding for loops... please

[FONT=Calibri][SIZE=3]I have been practicing actionscript 3.0 for at least one year now and still confused about the “for loop” statements.[/SIZE][/FONT]
[FONT=Calibri][SIZE=3]I copied the following code from this forum just to use it as an example, and it looks like this code will generate 100 rainDrops that will move down but where I’m confused is with the” (var i:int=0; i<100; i++) I thaught this was just an expression to see if the loop should continue or simply stop, something like “(if i less than 100){ do this as long as “i” is less then 100} but it looks like it is telling it to create 100 rainDrops “(if i less than 100){create 100 rainDrops) why? [/SIZE][/FONT]
[FONT=Calibri][SIZE=3]Can someone explain how “for loops” work and how to read them?[/SIZE][/FONT]
[FONT=Calibri][SIZE=3]Also how can I make this code to create raindrops more than once not only on ENTER_FRAME?[/SIZE][/FONT]

[SIZE=3][FONT=Calibri][FONT=Calibri][SIZE=3]var rainDropArray = new Array();[/SIZE][/FONT]

[FONT=Calibri][SIZE=3]for(var i:int=0; i<100; i++) {[/SIZE][/FONT]
[SIZE=3][FONT=Calibri]var rainDrop:RainDrop = new RainDrop();[/FONT][/SIZE]
[SIZE=3][FONT=Calibri]rainDrop.x = Math.random() * 550;[/FONT][/SIZE]
[SIZE=3][FONT=Calibri]rainDrop.y = 0;[/FONT][/SIZE]

[FONT=Calibri][SIZE=3]this.addEventListener(Event.ENTER_FRAME, moveDrops);[/SIZE][/FONT]

[FONT=Calibri][SIZE=3]function moveDrops(e:Event):void[/SIZE][/FONT]
[SIZE=3][FONT=Calibri]for(var i:int=0; i<100; i++) {[/FONT][/SIZE]
[SIZE=3][FONT=Calibri]rainDropArray*.y += 1;[/FONT][/SIZE]