Bsd is a complete package and tested as such. All the software and everything. It's like windows, when it's released you install it and you get wordpad, edge, calculator etc. Bsd is the same that way. Linux is just a kernel, with the distributions bolting on the gnu software. I know it sounds kinda the same but it's not.

Also the license. With Linux I think you need to cite it's use and you can't charge for something build with it (of course there's exceptions, like packages you create do not need to be for example), but bsd license is the most permissive. You can charge a customer for it and dress it up however you want.

No systemd.

There's some other stuff too