What's the purpouse of crosshatching?

I presume I'm looking at a ground plane here. What's the purpouse of laying it out in that sort of crosshatch pattern? Does it do something to reduce noise in the ground signals, or is it purely for aesthetic reasons?

It provides thermal relief, that is it doesn't suck all the heat out of your soldering iron. Also it balances the thermal load (or copper balance) during manufacture when it is going through the oven or over the solder wave.

Good to know. Thanks!

Mike, I appreciate your explanation as this is something I've wondered about in the past but never gotten a satisfactory answer.

A year or two ago, I saw a post on another electronics forum that suggested the crosshatch was often used on analog circuits, and a solid pour on digital circuits. I can't wrap my head around any sort of reasoning behind this convention; is there any truth to it? Your explanation seems much more plausible.

Just want to add a somewhat unrelated fact because i learned about it recently: Some hobbyists prefer to use cross hatching when making their own pcb via toner transfer, because laser printers deposit more toner on edges than on solid areas.