Question about knitting instruction

hello everyone, Iam very new to knitting and am trying to knit a simple pair of mittens. My question is: what does knit into front and back of stitch mean exactly? The pattern says: Row 1 K 7 kf&b twice,k 7 - 18 sts.
Also does k2tog mean knit twice in the same knit? which would be decreasing,or am I wrong/
I would appreciate some whenever someone has time
Thanks so much

KF&B is an increase. You are going to knit the stitch but before you take it off the needle, you’re going to knit into the back of the same stitch. So, after you’ve wrapped the yarn and are ready to remove it from the needle, bring the right needle around to the back of the left needle and insert the right needle into the stitch you just knitted. Wrap the yarn as you would to knit and bring the needle back under the first stitch and off the needle.

I forgot to answer your 2nd question: K2TOG is a decrease. Instead of putting your needle in one stitch, you’re going to put your needle in two stitches and knit them together.

Knit into the front and back is an increase. You knit into the front loop of the stitch as normal, but don’t slide it off. Then knit into the back loop of that same stitch and then slide it off. You’ll have two stitches instead of one.

K2tog is a decrease. Put your needle in through both the second and first stitches on the left needle in the direction you normally knit (so second stitch first), and knit them both at the same time.

And welcome!