Perennials come up every year
biennials like wallflowers are grown this year then flower next and often don't grow again or are poor specimens
annuals you sow in spring, they flower then usually die...

Pamg has just about summed it up nicely. But just to add a bit more confusion, a lot of tender perennials that are native to warmer climates and flower every year, are treated as annuals because the winter frost over here will kill them off.

Or even biennials can be tender perennials Myron.....?
some wallflowers and sweet williams last a few years , but never really as good I think....

Thankyou that is what I thought