Permaculture is a branch of ecological design, ecological engineering, environmental design, construction and Integrated Water Resources Management that develops sustainable architecture, regenerative and self-maintained habitat and agricultural systems modeled from natural ecosystems.
The term permaculture (as a systematic method) was first coined by Australians Bill Mollison and David Holmgren in 1978. The word permaculture originally referred to “permanent agriculture” but was expanded to stand also for “permanent culture,” as it was seen that social aspects were integral to a truly sustainable system as inspired by Masanobu Fukuoka’s natural farming philosophy.
“Permaculture is a philosophy of working with, rather than against nature; of protracted and thoughtful observation rather than protracted and thoughtless labor; and of looking at plants and animals in all their functions, rather than treating any area as a single product system.” (Bill Mollison.
There are several publications with permaculture, so you will be pleanty of information if you are interested.