Flex – how much a badminton racket’s shaft can, essentially, bend – varies from flexible to stiff/extra stiff. A flexible badminton racket allows more movement in the head to generate power. Flexible shaft badminton rackets – are also easier to play with and more forgiving, so ideal for the beginner.
Medium flex badminton rackets – allow a bit of movement with some accuracy. A decent middle of the road option.
Stiff shaft badminton rackets – are more accurate for shuttle placement. They can be harder to generate power. You need good technique/quick arm speed to generate power from a stiff/extra stiff shaft racket. Most elite players use stiff shaft badminton rackets.