watch this video from about the 3 minute mark to the 5:30 mark, he does a really good job of explaining those antennas.
https://www.youtube.com/watch?v=j6LuEhuU-l8
the video isn't designed around phantoms specifically but that 2.5 minutes of explaining signal patterns is useful. right there towards the end he says "that's why people are going to cloverleaf style" antennas but now there are tons more options for example FPVLR makes what's called a "pentalobe" with 5 lobes instead of 4 (cloverleaf/pinwheel = 4 lobes)
the main idea like I said is to get a spherical (instead of linear) signal pattern being output from your transmitter, which makes picking up the signal on a receiver much better and easier.
on the receiver side, like I said omnidirectional antennas work nice at short range because you don't necessarily have to worry about keeping the antenna pointed directly at the Phantom, it'll pick up signal from any direction but because of that they can't pick up weaker signal at farther range. for longer range you need a directional antenna which you DO have to keep pointed at the phantom (fpv transmitter, technically) but it can snatch a much weaker signal out of the air.
fwiw, my experience with range testing my FPVLR's went like this: I always have the pentalobe (the one in the 120 bundle) on the transmitter. so that being the case, in a zero-interference environment with the pinwheel from the bundle (omni) only on my receiver I got right around 650m before the signal wasn't really useable anymore.. that's with the best most premium antennas.
When I switched to the helix I went out over 1800m (1 mile = ~1600m) and still had rock solid FPV like it was sitting right next to me. this is with a 400mW TS353 transmitter btw.
obviously in a higher interference (urban) environment those numbers are reduced. cheaper antennas would just mean less range, like the guys running just a pair of the $50-$60 cloverleaf antennas usually get around 400m or so before their signal breaks up. I've also recently worked on a buddy's Phantom and he has a super cheap like $20-$30 pair and I can only get 100m over the city at best.
my point being, the more money you spend on better antennas the farther they work... so buy appropriately. I completely acknowledge that not everyone needs super premium 2km range