What is the role of download manager!!!. Is it magically increase connection's speed.
How it works???
Which is da best download manager!!!

I dont quite know what you mean by Download Manager, do you mean like Firefox's Download Manager? If so, then no it does not increase connection or download speed, what i have found it reduces my download speed, but what it does is keeps all the files and things you have downloaded in a list allowing you to see them.

But you may mean something similar to Download Accellerator Plus or DAP as it is more commonly know as, then yes it does increase download speed, but not connection speed. It too, like Firefox's download manager has all the files you downladed in a list that tells you if they are paused, downloading or stopped and the percentage and how many MB or KB downloaded.

To increase connection speed you would have to have a program such as modem booster, i think you need dial up for it to work, I cant really help you there but try your good friend Google. I hope i may have provided the answers you were seeking.

Its usually a program that helps you to accelerate downloads and manage your downloads... If you want more resource about download manager just google it... And some of the more popular download manager are flashget and I'm currently using leechget...

The main role I have for a download manager, (mainly the ones like get right and such Firefox's default one sucks) is to stop corrupt downloads. When I had dial up, I found that sometimes when I downloaded 5Mb or more it would sometimes end up with a corrupt file. Download managers seemed to fix this problem.

Another use I have found is that they allow you to resume downloads, which was also great on dial up, as I could download it in segments. The only problem was that some servers didn't let you do this (File-Planet), which was a pain, especially when you found this out when you had stopped downloading on 30Mb

when you d/l a file straight from IE or FF they can get corrupt like yacoby said but also the speed increases a lot. also like yacoby said you can continue downloads. it increases speed by making multiple connections to the server it downlaods from, so it starts from various point in the download while IE or firefox start from the start which would take longer. if you want download flashget (www.flashget.com) and when your downloading somehting then look at the graph/log, and look at one of the jets, you can see it's downloading from multiple points.

Download manager is require if you dont want to download the complete file at once. It also searches for any available mirror sites to download fast. Also the whole file is downloaded in parts so that the complete process is fast.
Get right is the best I beleive.

I don´t use any download manager (apart from mozilla one) right now. I used GEtright and I agree... I suppose that the fact that it download the file in parts, helps to make the download faster. I suppose its like it downloaded 3 or 4 files instead ofone and then, join them to conform the original, maybe. The best about ehem for me is the fact that you can pause downloads and continue them later.

ive been content with the mozilla firefox download manager, it seems to work fine for me, and ive never had any problems with it

I have used a download manager or should I say a download accelerator before. And yes it did increase the download speed of your internet connection but it does not increase your internet connection speed like some of the posts has said.

Personally, I do not like this download accelerators because they give you adware, and rubbish such as that. I will just stick to Mozilla Download Manager, keeping it natural and free of all those rubbish adware.