I’m stuck on understanding this pattern row

[Sandie131201]

So I’m fairly new to crocheting. And I’m currently trying to crochet a Jellyfish from the crochet book of Whimsical Stitches by Lauren Espy. But I  do not understand how to do this row 

“Through FRONT loops only, *Sc 1, hdc 1, sc 1 in one st, sc 1 in next st,* 21 times. (84 sts) Sl st and fasten off.”  
 If anyone could put it into simpler terms for me that would be great 

[bgs]

This shows what working in front loop only means.  You work all stitches in this round in the front loops of previous round.

https://www.crochetconcupiscence.com/how-to-crochet-in-front-loop-only-and-back-loop-only/

You make 1 sc and 1hdc and 1 sc all into one stitch (the front loop of that stitch) of R 14.  You make 1 sc into next stitch (front loop) of R 14.  Repeat this entire sequence 21 times.  

In other words you are making 3 stitches into every other stitch of R14.  

Stitch count given for R15 is 84 stitches.

3 stitches (sc, hdc, sc) x 21 = 63 

1 sc x 21 = 21

21 + 63 = 84 stitches

[Sandie131201]

28 minutes ago, bgs said:

This shows what working in front loop only means.  You work all stitches in this round in the front loops of previous round.

https://www.crochetconcupiscence.com/how-to-crochet-in-front-loop-only-and-back-loop-only/

You make 1 sc and 1hdc and 1 sc all into one stitch (the front loop of that stitch) of R 14.  You make 1 sc into next stitch (front loop) of R 14.  Repeat this entire sequence 21 times.  

In other words you are making 3 stitches into every other stitch of R14.  

Stitch count given for R15 is 84 stitches.

3 stitches (sc, hdc, sc) x 21 = 63 

1 sc x 21 = 21

21 + 63 = 84 stitches

Thanks so much! It’s turning out great!