Forum:What is build?

Alright, so im a bug fan of the Fire Emblem series and I have been playing Fire Emblem for quite some time, however, I still do not know what "build" is, I mean what does it actually do? Does it effect stats or something of the sort. I ask because there are items that increase "build", and im not sure if thats a good thing :P. Any help with answering my question would be much appreciated.

-Shad0wl1f3