I will add, .com: Commercial (for-profit) websites IE: Rick's, Camaro Central
.net: Network-related domains IE: Team Camaro, Yenko Supercars
.org: Non-profit organizations IE: CRG
being a .org is more like a free information, like a library, that would be used for research.
Whereas, .net (meaning within a network)could encompass broader "services", like classifieds, generally, .orgs do not get into selling/buying or want ad services.
.coms, of course are the most common and cover most "for profit" content.