die Bettwäsche
bed linen
The complete set of textile covers for bedding, that is, for the blanket and pillow.
Ich liebe den Geruch von frisch gewaschener Bettwäsche.
I love the smell of freshly washed bed linen.

bed linen
Loading your saved state.
bed linen
The complete set of textile covers for bedding, that is, for the blanket and pillow.
Ich liebe den Geruch von frisch gewaschener Bettwäsche.
I love the smell of freshly washed bed linen.

'Bettwäsche' is a compound noun made from 'das Bett' (the bed) and 'die Wäsche' (laundry/linen). It literally means 'laundry for the bed' and refers to the covers for pillows and blankets.
Am Samstag ist Waschtag für die ganze Bettwäsche.
Saturday is laundry day for all the bed linen.
'Bettwäsche' (bed linen) is a collective term and is almost always used in the singular, even when talking about several sets. If you want to emphasize the number, you say 'eine Garnitur Bettwäsche' (one set of bed linen) or 'zwei Garnituren Bettwäsche' (two sets of bed linen).
Ich habe mir zwei neue Garnituren Bettwäsche gekauft.
I bought myself two new sets of bed linen.
In everyday life, 'Bettwäsche' (bed linen) is often combined with certain verbs: You can 'wechseln' (change), 'abziehen' (strip off), '(frisch) beziehen' (put fresh linen on), or 'waschen' (wash) the bed linen.
Könntest du mir helfen, das Bett frisch zu beziehen?
Could you help me put fresh linen on the bed?
duvet / comforter
'die Bettwäsche' and 'die Bettdecke' both belong to the bed and are therefore easily confused. 'die Bettdecke' is the warm duvet or comforter itself, which you cover yourself with. 'die Bettwäsche' refers to the covers, for example the cover for the duvet and the cover for the pillow. You normally wash the 'Bettwäsche', not the whole 'Bettdecke'. The 'Bettdecke' is often inside the 'Bettwäsche'.

Am Samstag wechselt Anna die Bettwäsche und legt frische Bezüge aufs Bett.
On Saturday, Anna changes the bed linen and puts fresh covers on the bed.
Meine Schwester nimmt im Winter eine dickere Bettdecke.
My sister uses a thicker duvet in winter.