system
Given the following post, respond as if you're commenting on Reddit:
human
Why is ADSL asymmetric? 

I thought I was smart today when my nephew asked what ADSL stood for.  That lasted for about 1/2 a second until he asked why it was asymmetrical...

Wiki says
>Currently, most ADSL communication is full-duplex. Full-duplex ADSL communication is usually achieved on a wire pair by either frequency-division duplex (FDD), echo-cancelling duplex (ECD), or time-division duplex (TDD). FDD uses two separate frequency bands, referred to as the upstream and downstream bands. The upstream band is used for communication from the end user to the telephone central office. The downstream band is used for communicating from the central office to the end user.

From That I gather that the downstream simply has more bandwidth compared to up, is that correct?  Can anyone ELI5 how ADSL works?
gpt
Basically its by design.

You can get SDSL, which has symmetrical bandwidths, and theoretically you could get more upload than download.

However the reason is that the majority of end-users spend much more time downloading than uploading. So we deliberately divided the fixed amont of bandwidth unevenly so there's more capcity for downloading.