You get what you pay for with this arrow rest. Do not expect any great accuracy and it will eventually wear down and need to be replaced.
The proper way to install it is horizontally. However some people don't know this and install it vertically... Which results in lots more inaccuracy as the arrow fletching ends up rubbing against the arrow rest way more.
There is also a particular style of cheap plastic arrow rest that is meant for either left-handed or right-handed bows, and you are supposed to rip off the section of the arrow rest you are not using - see image below. Again, people don't know that they are supposed to cut off / rip off that section, and thus suffer from unnecessary inaccuracy simply because they don't know any better.
There are many different designs of arrow rests like this (see the image on the right and the two images below) - and in theory people could make their own using nothing more than a paper clip and tape, and it would work practically the same way.
The principle is simple. The arrow rests on top of a tiny bit of wire and it flips out of the way as the arrow passed by, causing comparatively little contact with the arrow - and thus improving accuracy.
Compared to a plastic arrow rest, a wire arrow rest lasts a lot longer. It will eventually wear down however. The wire will become bent, the plastic on the side of the arrow rest can wear down, and so forth.
NAP and similar companies make a variety of spring-loaded arrow rests wherein the archer can adjust the spring to the weight of the arrow. When used the force of the arrow passing by brushes the arrow rest out of the way, creating very little friction.
For best results the archer should try to adjust the spring so it matches the weight of the arrows perfectly - and then always use the same weight of arrows when shooting with that bow.
This style of arrow rest is commonly used on compound bows, but it can also be used on recurve bows that are compatible.
Traditional archers tend to favour a very traditional way of doing things - in this case an arrow rest that resembles fur. The arrow rests upon the fur, brushes over gently and the fur barely touches it.
Whether an archer uses faux fur, felt, hair, carpet or similar materials, the principle is the same - a furry carpet that brushes gently against the arrow, thus minimizing contact and increasing accuracy. (Personal Note - Years ago I made a similar arrow rest using sheepskin - it was very furry and I had to trim it down quite a bit. It looks like the bow has a moustache.)
The Whisker Biscuit Arrow Rest (shown below) follows the same principle, but is usually used for compound bows. The arrow brushes against plastic whisker that surround and entrap the arrow. Some archers trip the whiskers back where the vane fletching rubs against the whiskers in order to minimize it further.
#5. The Drop Away Arrow Rest
This last type of arrow rest drops down out of the way midshot, in theory allowing the arrow to pass by with zero contact with the arrow rest. It is spring loaded to make the process very fast. It is tuned and attached (usually) to a compound bow cable. When the shot is released, the cable moves, triggering the arrow rest to drop away. This creates an extremely accurate shot, but the arrow rest needs to be tuned properly to achieve this desired result.