Depends on location and conditions. A tent is free standing and generally has screens to keep out the bugs, which is nice in some areas. A tarp can be lighter and suffice if you have trees to tie it to. If I have to carry poles, I will probably just carry a tent. In some areas and weather I prefer a hammock, but again you need trees. I normally do not put up a shelter unless I am expecting precipitation or strong winds.

Good points all. Thanks wiley.

If I don't put one up it rains everytime. Thanks montanero.

I have not been camping in a long while, but I always used a tent as an adult.

I am giving some serious consideration to taking up camping again. Car camping is pretty easy. You can bring whatever you want with you. Backpack camping requries more thought. Never tried that before, although when I was a kid I did some walk in camping with a youth group.

Most of the time when I was a kid and we were at a regular campground, I slept out on top of a picnic table. Worked pretty good except when it rained. Even with a tarp strung up over the table, the wind would blow rain on me and chase me into the camper or a car.

My biggest concern with tarps is how weatherproof (or not) they are, especially a small one (like 5X7). I don't see anyway that it is as weatherproof as a tent. Has bug issues too.

Having said all that, I am getting old and no longer want to sleep on the ground or a table. I am thinking a hammock with some kind of bug screened bivy under a larger tarp might be the setup for me.

For car camping, I may just get a cot to sleep on.

I bring an Aerobed. If the campsite isn't electrified I run an inverter from my car to inflate and deflate it. Camping without the agony.

I have both. Each has its merits. Tarps are great for the weight and are easy for a night or two. When I section-hike the AT, I'll likely bring a 3-season 1-2 person like a Eureka! Apex (or something close). Don't need to be between shelters with small protection in emergency conditions.

I bought a tent which fits in the bed of a truck. An Areo type bed with a foam topper is a nice combo in it.

The AT was a dream of mine. But my knee would never make it now. Thanks for responding Finn.

When "car camping" I prefer to sleep in my Jeep. Comfy, quiet, and very wind resistant. (As compared to others in the party whose tents collapsed/flooded so they slept in their trucks without prior preparation and after being soaked)

When backpacking I prefer a tent. I've thought long and hard about bivy sack & tarp but there have been too many instances of having an inch of hail cover the ground just about sunset leading to a damp/cold environment that suggests the tarp would be ineffective as shelter (in my hands).

When dayhiking I carry an army poncho as both a rain cover and as an expedient shelter. (Trading a lower quality of shelter against the chance of even needing it.)

I have both, but use tarps 95% of the time in the backcountry.

When backpacking I love to be able to crawl into my sleeping bag
when it gets cold, and set my stove up just out from under the tarp. In very sunny treeless places, a tarp can be used for shade to read a book or take an afternoon nap. And I have a great view.
Tents get too hot.

I bring both car camping. I have a tarp for rain or shade when cooking and dining,a tent for privacy when sleeping.