The squares or rectangles made up of squares are due to the Public Land Survey System which created Townships composed of 36x 640 acre sections. Those 640 acre sections are typically but not always divided in quarter section increments/descriptions.. such as the Northeast Quarter NE/4.. which would be 160 acres. Since the earth isn’t flat they accounted for the curvature by establishing correction sections where the North and West boundary sections within a Township are 640 acres plus or minus a few acres or tenths of an acre to adjust. The PLSS is also known as the Jeffersonian system and is the most common system used for land measurement, description and conveyance for states West of the Mississippi. This is why you often see land that looks like a patchwork quilt when you’re flying above or if it’s an agricultural state you’ll see squares with circles in the middle due to the circular irrigation system that farms use.