Can You Briefly Explain Oxgangs And Yardlands?

Oxgangs and yardlands -
In the typical pre-enclosure farming system, villages were surrounded by large, hedgeless, `open fields' that were farmed in strips. In the South, an individual farmer's holding could be called a yardland (O. Eng. Law.) A measure of land of uncertain quantity, varying from fifteen to forty acres. The holding was called  an oxgang in the North, typically consisted of about 20 acres of land lying in 70 or so strips, or ridges, scattered throughout a township, no two ridges lying together. As a land measure, the oxgang was no certain quantity, but as much as an ox could gang over or cultivate. Also called a bovate. The Latin jugum was a similar term, which Varro defines "Quod juncti boves uno die exar re: possunt."
   Eight oxgangs made a carucate. If an oxgang was as much as one ox could cultivate, its average would be about fifteen acres.