Badminton shuttlecocks are usually made of two types of material, feather shuttlecock or synthetic (plastic or nylon) shuttlecock.
Natural = Feathers = Involves killing birds!
Synthetic = Plastic or Nylon = More ethical
Beginners prefer to use synthetic shuttlecocks as they are more durable and relatively inexpensive compare to the feather shuttlecocks. Feather shuttlecocks are not long lasting due to the fact that they are made from natural feathers. Wear and tear such as damaged feathers or loosing a feather on a shuttlecock will affect the flight stability and need to be replaced. Shuttlecocks can made from goose or duck feathers. Premium shuttlecocks are said to be made from goose feathers. Other shuttlecock manufacturers also supply duck feather shuttlecocks that are as good as grade one goose feather shuttlecocks.
Depending on manufacturers, there are 16 or 14 feathers on a shuttlecock. The feathers are arranged in a overlapping circular manner and attach to a weight at one end which can be made from natural cork, composite cork or plastic base material.
Shuttlecocks come in different speeds. Some brands use color bands on the base to different speed, green for slow, blue for medium, and red for high speed.
Green = Slow
Blue = Medium
Red = Fast
However, temperature can also affect the shuttlecock in-flight speed. Hot weather tends to make shuttlecocks fly faster while cold weather tends to make them fly slower. So in colder countries or an air-conditioned competition halls, use a slightly faster shuttlecock.
Synthetic shuttlecocks are cheaper and more durable so they are usually used by novices, schools and clubs for practicing. Disadvantage of synthetic shuttlecock is that it has bad in-flight stability but it can last for many practice sessions. As beginners gain more experience in the game, they can use the feather shuttlecocks to bring their skilled to the next level.
The good news is that Badminton World Federation (BWF) has already approved the use of synthetic feather shuttlecocks at BWF International sanctioned tournaments of all levels in 2021. This a huge step away from using natural feature shuttles and helping ensure long-term sustainability. BWF found that synthetic feather shuttle could reduce shuttlecock usage up to 25 percent, providing a significant environmental and economic edge for badminton going forward.
Source: http://shuttlecocksonline.com/types-of-badminton-shuttlecocks/
Special Note: At our club we use nylon shuttlecocks for all our training sessions, social games and competition games.