I hope I've put this post in the most appropriate section...

After reading posts on this site for over a year, I finally got around to joining so I could ask a question that has flummoxed me for years...What is meant by "crumb?"  I've been cooking and baking for 20 years but only started baking bread about a year ago.  I know that the word "crumb" is used in reference to cakes as well as breads, but I've never understood what it's referring to and never bothered to ask anyone--until now.  So bakers, can any of ya'll enlighten me? 

Thank you and happy baking! :)

>AKAlicious