Synthetic carpets are made from plastic resins that are made in fibers. These fibers are see through and generally stronger then natural carpet materials.
Synthetic carpets start off as plastic chips actually then melted in a machine and forced through a spaghetti like strainer. After this process they are crimped, this is the wrinkle or style you see. Olefin and polyester carpets don’t hold their crimp very well so they often wear very quickly in high traffic environments. Not a great choice for living rooms.
The fibers are then heat set to hold the twist you see, this creates a memory so the carpet springs back after you step on it.
Nylon- Nylon carpet was the first available to give homeowners wall to wall carpet. Previously most homes had hard floors with area rugs over them. Current estimates is 60-70% of homes have a nylon carpet, making it by far the most popular.