Place stitches on waste thread?

I am pretty new to the knitting community. I have been teaching myself using youtube or kntting sites like this but I have finally come across something that I can’t seem to understand or find. The intructions say:
“at this point I would place all remaining stiches on a waste thread. As you work the fingers, keep the thread in place in case you need to rework any of the fingers”

I have no idea what this means so any help would be wonderful.

You’re going to put those stitches ‘on hold’ for later. Use a tapestry needle or large-eyed needle and pull a strand of contrasting color yarn through the stitches and then remove the knitting needle. Now the stitches will be held on the spare yarn.

When you get to the point where you need these stitches, you reinsert your knitting needle through without losing stitches. This pattern suggests leaving the spare yarn in the stitches as you finish the fingers in case you need to rip back–your spare yarn will serve as a lifeline that you can rip out to and not lose stitches.

a fine detail

you could put all the stitches onto a stitch holder…

BUT stitch holders tend to be stiff (some are sort of like a DPN, with a cap on each end, other are like giant safety pins with out the spring coil)

and because they are stiff, they can get in the way of the knitting (especially when you are knitting a dozen or so stitches for a finger on a glove!

if you follow Ingrid detailed directions, it will be easier to work the fingers!

and as she says, LEAVE the yarn in the stitches…
then if you need to frog… you can frog down to the ‘thread’ (life line) and its easy to pick up the stitches again, and start over!

I like to use pearl cotton for this… (its smooth and slippy!)

DMC (the embroidery floss company) makes packs of pearl cotton called “crafting cotton” it looks (at first glance) like heavy embroidery floss, but look again, and you realize its spun tighter (its doesn’t separate into strands the way embroidery floss does.)

a pack of 10 skeins (each about 10 yards) comes in a selection of colors (light, dark, white and black) and will last half a life time (and cost about $3!)

Many people use dental floss too.