What is a self-sufficient community and why was it necessary during middle ages?

A self-sufficient community is a community that produces everything that is needed on their own. It was necessary for them to have self sufficient communities because in the early middle ages there was a decline in trade causing many goods to be difficult to get. 

The mountains on the east would be taller

Economic success prussia had a very strong economy, partly due to the success of the zollverein. stronger prussian army king wilhelm wanted to build a bigger, stronger army but was blocked by the prussian landtag (parliament).-credits to google for putting answer -credits to slideshare for making answer-credits to me for putting answer on brain.ly