Your tent can make all the difference on a backpacking adventure. But selecting the best model for you depends on a few factors: trip frequency, duration and location, what the weather is likely to be, the distance you are you planning on carrying your tent, whether you want to be by yourself or with other people (or pets), which additional features are most important to you and, of course, how much you want to spend.

Types of Shelters
Double-Wall Tents
Double-wall tents have three primary parts: (1) an inner tent with a waterproof floor and non-waterproof canopy (almost always mesh), (2) poles, and (3) a waterproof rainfly. Most double-wall tents are quite easy to pitch, offer complete protection from rain and bugs, and are comfortable.
However, they also tend to be the heaviest type of shelter, owing to a dedicated set of poles and multiple layers of fabric. Double-wall tents come in a couple of basic sub-varieties:
Freestanding tents
When you close your eyes and think “tent”, it is probably a double wall freestanding model. This variety stands up entirely on its own (with ground stakes to hold it in place). It is most often used for car camping, overnights, or any backpacking trip where weight is less of a concern. More durable models can be used for harsh weather and winter camping, as well.
Semi-freestanding tents
These tents have their own set of poles but also require a few stakes or guy points to pitch at full volume. This style is increasingly popular because it offers the security and comfort of a double-wall tent while reducing weight by removing some of the pole structure. There are even several models that can be pitched with a pair of trekking poles instead of the included poles, which reduces carried weight even more.
Tunnel tents
Tunnel tents are a type of semi-freestanding tent that has a unique pole structure. They have one or more hoop-shaped poles and rely on guylines to stand upright. Tunnel tents generally have a higher space-to-weight ratio than other styles (for the geometry people out there, think of the volume of a cylinder versus a triangular or rectangular prism inscribed in that cylinder).
Thoughts on doors: Within the world of double-wall tents, there are many variations on door size, shape, and zipper configurations. They can be broadly broken down into three types: (1) double side door (2) single side door, and (3) front-end door. We find that double side door tents — those with an entrance on each side — are the most comfortable and most versatile. When camping with more than one person, each person having their own entrance and corresponding vestibule is a huge plus. It also means that if you are setting up on a small or irregular tent site, there is more flexibility with the orientation of the tent. If a boulder or tree is blocking one door, there is a second one on the other side. Front-end door models — those with just one door positioned at the head of the tent — also offer equal access to both people in a two-person tent but it’s harder to exit without disturbing the other person. Single side door tents — those with just one door on one person’s side — work well for individuals but are the least comfortable if there are two or more people; the person on the far side must climb over the person closest to the door to get in and out of the tent.
Going Big: The Value of a Three-Person Tent
Many tent models come in some combination of one, two, three, or four-person versions. Two-person tents are by far the most popular. Usually, the difference between a two and a three-person version is the width. Manufacturers will add around 20 inches (the width of a standard sleeping pad) and voila, your tent is now fit for three! Occasionally, the extra floor space comes with a little more headroom and maybe some more length, but this is not always true.
If it is possible that you will bring a couple of friends or your dog on your trip, then it makes sense to look at the three-person version of whatever model you are scoping out. You could certainly opt for a more spacious 2P, and you would almost certainly pay less for it. But consider this: if the tent you have your eye on is a lightweight 2P, it is almost certainly going to also be lightweight in its 3P format. In other words, the 3P version of a lightweight tent may still be lighter than a lot of 2-person tents, so if space is equally important to you as weight, consider sizing up.
Tarp Tents
Tarp tents are single-walled shelters with a built-in floor and bug netting. What’s a single-wall shelter? It’s similar to a double-wall shelter except instead of a mesh canopy overhead with a separate fly attached over the top of that, the rainfly is the ceiling (and is permanently affixed). The benefits of these models are that they have fewer parts and tend to be much lighter than double-wall tents.
They also offer complete protection from the elements. Their biggest drawbacks are that they are susceptible to interior condensation, meaning you might wake up damp in the morning (remember, all that breathable mesh just got replaced with a solid piece of fabric). They are also the least adaptable because all of the parts are attached. Tarp tents pitch with dedicated poles, trekking poles, or a combination of the two.