We �re all teachers, so of course we love to share information.
Litter is trash that people throw down outside, so the bins have "litter" on them, because the trash you deposit there would be litter otherwise.
As I understand it, rubbish is a somewhat general term for anything you want to get rid of, and generally in a large amount (but not absolutely necessarily).
Waste is generally some sort of byproduct, such as old chemicals from a factory, discarded medicines and things resulting from medical procedures, human or animal excrement, etc.
Garbage is usually discarded food products.
There �s also "trash", which is a very general term for the discarded items from everyday life.
That �s how I understand these words. I �m sure some others will have great things to contribute.
Bruce