What do ridges mean in knitting?

I’m new to knitting and would like to know what the pattern means when it says: “Knit in rounds; knit the first round, purl the second round, until 3 ridges have been worked.” Why can’t they just say to repeat this 3 times—or however many times it takes?
My question is: How many times do I need to repeat the first two rounds to get 3 ridges?
Best regards, Ines 

Hi Ines,

I’ve been knitting for about 50 years, and this is the first time I’ve seen anything about ridges in this context.
Maybe you should ask the author what she means by that.

When you knit in rounds, alternating one round of knit stitches with one round of purl stitches, it’s basically like garter stitch. In that case, I’d understand a “groove” as the indentation created by the knit stitches, while the purl stitches always look slightly raised. That would mean three repetitions, or 6 rounds.
But you’re right—it’s phrased very strangely; I’ve never seen it written that way before.

Yes, I could do that. Thanks for the helpful tip. 

That sounds like a Go...l translation....
Actually, we usually talk about “garter stitch” and not “grooves”.... 🙈🤷
Veronika explained it well. It’s described a bit oddly in the pattern.... 

Great, thank you so much for your help 👏