Hi folks!
I am a beginner, knitting a simple tank top using magic loop. I am trying to understand something – could someone explain to me why one must separate the stitches in half and knit in “rows” in this style instead of just knitting around and around and around without turning the work, using stitch markers to know where you are?
Thank you! 
Maggie
Can you give us the name of your pattern/designer? It might help us understand your question. Does the pattern specify magic loop?
You don’t often work in rows when using magic loop, but for something like a tank top, part of it is worked in the round (the body), and part of it is worked back and forth in rows (the upper body and straps).
It’s usually possible to NOT use magic loop…you can work the body in the round as usual, then switch to working in rows when you get to the part above the armholes.
Again, knowing the exact pattern you’re using will help. You can post small sections of the instructions, just not the entire pattern to protect copyright.
Perhaps what you’re describing isn’t really “rows” but instead it is working in tne round with magic loop which might sort of appear to be rows as the stitches are divided between the 2 needle ends to enable working in tne round.
Often magic loop is used for a circumference in the round when a knitter doesn’t have a cable small enough to work around and around as the number of stitches cannot stretch around too large a circumference.
Magic loop can also be used just out of preference as some knitters like the method more than a shorter cabl or a set of double pointed needles.
If you are only working the right side (public side of the fabric) then it is working in rounds or knitting in the round.
If you are working the right side and also the wrong side (the hidden side of the fabric) then this is knitting flat or knittinģ in rows.
It’s not unusual for sweater patterns to be worked partly in the round and partly flat.