Biennial, perennial etc Please help me understand!

[SeeYouEntee]

Can anyone explain what these terms mean?

I know that a biennial has a life span of two years, and a perennial lives for a few(?) years, but when they die is that it? Do you have to get more plants? Or do they propagate themselves in some way?

And are they always deciduous?

Thanks!

perennials should last forever and grow into big shrubs/trees etc. if they die they need replacing.
biennials same, when they die you need to replace.
don't know about the deciduous - wouldn't think so.

biennial flowers the year after you plant it perennial lives technically always unless you kill it and annual lives one year only no they are not always deciduous, perennial plants propigate in different ways its hard to explain some of them spread like a weed some are like slow growing shrubs and are less of a problem try the gardening section on the bbc website ive always found that to be useful

Thanks you both!!