Arch Pattern

Dear users, dear authors,
what is an arch pattern and what do you use it for?

Would anyone else like to add anything?

I had to think about it for a bit because the term “arc pattern” didn’t mean anything to me at all. I just Googled it, and the top result said, “Did you mean wave pattern?” I can picture that better.
Wave patterns are basically created by increasing in some places and decreasing in others, always alternating. So, to put it simply, you make a few yarn overs in one spot—knit 1, yarn over, knit 1, yarn over—and then you’ve increased by three stitches. You then have to decrease these stitches again later by either working slip-stitch decreases or knitting stitches together, so that the number of stitches stays the same, and the waves are created by alternating between increases and decreases.