If you’re researching double-wall backpacking tents, you’re likely to see the terms “semi freestanding tent” and “freestanding tent.” These describe the architecture of a tent and how the poles are configured to set it up.
A semi-freestanding tent has one or more poles to hold up the tent body, but parts of it, most often the corners of the floor have to be staked out using tent stakes to stretch the floor out fully. A good example is the REI Quarter Dome SL 1, which has one tent pole that expands to form a tripod structure with three “legs”. Two of those legs slot into the corners at the head-end rectangular floor, while the third leg attaches to the mid-point of the foot-end of the floor, not the corners (see picture below.) Those corners have to be staked out separately to fully expand the floor and to keep the inner mesh from passing condensation to your sleeping bag or gear.
The Big Agnes Fly Creek HV UL2, the Big Agnes Tiger Wall UL 2, and the Nemo Hornet UL 2 are all semi-freestanding tents that have this tripod-style pole structure. The advantage of semi-freestanding tents is that they are lighter weight and have a smaller packed volume than many freestanding tents. Their tripod-style poles take up less space and are only about 3/4 the size of freestanding tent poles.
Freestanding tents, in contrast usually have poles that attach to all four corners of a rectangular floor plan, so that corners don’t have to be staked out. This is advantageous on surfaces like rock ledges, sand, or wooden tent platforms where it can be difficult to stake out a tent (See: How to Set Up a Tent on a Wooden Platform.)