defining crumb in bread baking

[isaac]

i packed all my books for my big move and i dont have my trsty culinary dictinary handy so here is my question.

what is the defanition of crumb in relation to bread baking. and what causes a bread to have a crumb? and is a crumb a good thing or bad thing?

thanks... i am having a brain fart. he he

[Spoons]

It's the interior of the bread.
It's defined by the hole structure.
Gelatinization of the starch.

It's a good thing!