This is the 7376th most frequent Swedish word.
ski
A ski is a long, narrow piece of equipment used for gliding over snow.
In this sentence, 'skidåkning' indicates the general activity or sport of skiing.
Skidåkning är en populär sport i Sverige.
Skiing is a popular sport in Sweden.
The word 'skidor' refers directly to skis used for skiing activities.
Jag älskar att åka skidor på vintern.
I love skiing in the winter.
Here, 'skidor' is used to denote the equipment, skis, needed for skiing.