The "tension" (or "lbs") of a badminton racket refers to the tightness of the strings-specifically, how taut they are pulled during the stringing process. Higher tension results in tighter strings and more direct feedback upon impact; lower tension leaves the strings relatively looser, creating a "trampoline effect" that makes it easier to generate power and launch the shuttlecock.
Generally speaking, low tension (around 18–22 lbs) is suitable for beginners; it offers a higher margin for error and requires less physical effort, as the shuttlecock rebounds off the strings more easily. Medium tension (23–26 lbs) is the most common range for amateur players, striking a balance between control, power, and overall feel.
High tension (27 lbs and above) is typically suited for advanced or professional players with a solid foundation. While it allows for greater precision and finer control over shot placement, it demands superior technique and power generation; without the right skills, the racket can feel "dead" or difficult to play with.
In short: lower tension is easier to play with and offers more bounce, while higher tension provides greater precision but requires more strength. The ideal tension depends primarily on your own strength and skill level.