What's an invisible seam?
I'm knitting a silk shrug from Erika Knight's classic knits. I never knit a sweater w/ seams. My first was a raglan w/out a simple seam. Reading ahead (I'm still knitting individual pieces), I notice it says to use "invisible seams." I looked at KH for a video on seams but I didn't find this. What is it, and where could I find a video for it?