Are chicken coops meant to keep the chickens in or other critters out?

A bear? No most wouldnt be able to keep out a bear, not even human homes are 100% bear proof.
Commercial coops are usually made only to keep birds in. If you are making your own, take yoir local predators into consideration. It would take a serious building to stop a bear and I dont know any kind of fence that would.
did you call your local fish and game? They remove problem bears on a regular basis. And a bear who goes into your yard for food is a problem...

Chickens runs are to keep the chickens in and hawks out, the coop is to keep predators out. Excepting hungry bears.

The only thing I know of to stop a determined bear is an electric fence, and that only works if you don't lose power.

I'd also be calling Fish and Game or Animal Control, depending on where you live.

Well, yeah, a tractor is just for daytime foraging, isn't it? 

 

Coop-- keeps away nighttime beasties. 

Run-- lets birds outside yet contained. 

Tractor-- nighttime food for bears?

We don't have bears in the part of MN where I live, but I do know that in the northern part of the state, they use electric fences to keep the bears away from the beehives.

In my experience and observation, pens, coops, barns, facilities for pretty much all kinds of animals, are all about keeping critters out. Keeping predatory critters out of your own critters. And keeping your critters out of places they shouldn't be, that are either unsafe for them or they are unsafe for that place. A good chicken facility keeps predators out of the chickens, and keeps the chickens out of the busy road out front, your garden, and your neighbor's property and garden.

That last one is something a lot of people that get chickens don't always think about. Especially when they like the idea of free ranging their chickens. Free range shouldn't mean free run of the country side, and off your own property, avoiding the expense and inconvenience of putting up a fence. Fine if you life in the middle of a couple hundred acres. Not so fine if you live on a couple acres with close neighbors. I've experienced the frustration and aggravation both ways...other people's dogs killing my chickens, but also other people's free range chickens eating all the seeds I just planted or destroying my just well started veggie garden. Once, for some reason i never figured out, a neighbor's flock of chickens adopted my front porch as a hang out. Chicken poop everywhere.

So i'd say coops and barns and pens and fences are for keeping critters out.

What I eventually came to for my chickens and around other small livestock, was chain link. My favorite for chickens is an outer fence of chain link, then an inner one of a smaller mesh chicks can go through, and chickens can't stick their heads out so as to get them bitten off by something. i've actually witnessed both  chickens and a muscovy dick lose their heads by just sitcking their head out through fence mesh where a dog was just waiting to grab them.