Why Internet Speed are so different?

[ElectroEnthusiast]

I'm unsure whether to ask this ques here, but i know ppl here may know the answer.
Why internet speed varies so much within a ISP?
He provides a package of 1mbps and also 16mbps.
Why is it so? And the cost of the packages will be different, higher for higher speed package.
Why this difference in speeds, when it's just connection computers together?
How the cost varies? Does speed somewhere related to power consumption of ISP?

 

[Nick C.]

Your ISP is basically reselling you bandwidth, so the more you use, the more it costs them. That's the simple explanation, but there's more to it than that, of course.


Why does bandwidth cost money? - bandwidth isp cost | Ask MetaFilter

 

[ElectroEnthusiast]

Hi Nick,
There arises me another ques, i see no difference b/w the term 'bitrate' and 'bandwidth'. What do you say?
I got quite good information from that link. But still, i have the ques. I didn understand how it costs them to 'resell the bandwidth'. How do they decrease the speed for a particular costumer? I really didn understand how it costs different to provide different bandwidth(though power consumption would be same).