Blanket pattern - don't understand square w/ cabling

Hey guys, I’m taking a look at this pattern (need to be on Ravelry to see it), and I’m a bit confused by the square with the cabling on it since I’ve never done cables before. The chart for one of the rows says " C 3 L C 3 R" (it looks like it spans 6 stitches). According to the pattern, this is what C3R and C3L mean:

C3R (P2 and K1):
Slip 2 to cable needle - BACK
K1, P2 from cable needle

C3L (K1 and P2):
Slip 1 to cable needle - FRONT
P2, K1 from cable needle

Problem is, [I]I[/I] don’t know what that means. Lol. If C3R and C3L each take up 3 stitches, then why do you only slip 2 stitches onto the cable needles? Why does it say to purl 2 and knit 1, but then you knit 1 and purl 2 from the cable needle? Can someone help to dumb it down for me? :mrgreen: Thanks!

C3R or C3L tells you the total number of sts in the cable (3sts) and whether it crosses left (L) or right ®. (P2 and K1) or (K1 P2) are a short description of what you will be doing and the rest of the instructions tell you how to do it. For C3R: Slip 2sts to a cable needle and hold in back of your knitting, knit the next st on the left hand needle and then purl the 2sts off the cable needle.
Same format for the C3L but the directions are: Slip 1 to a cable needle, leave the cable needle in front, purl the next 2sts from the left hand needle, and then knit the 1 stitch from the cable needle.