A Granny Square is a total classic within crochet techniques. It gives you endless possibilities, to create small pieces, many kinds of garments and all the way to a big blanket.
The fun in working with grannies is that you can put many of them together to create a bigger structure or shape. And though you can find different variations, there is the classic Granny Square design, which is super easy, made of basic stitches, with a repetitive set of rounds with increases in each corner, to grow your squares as much as you want.
This basic Granny Square is crocheted in the round, in closed rounds, starting from the center. Ch 4, sl st in first ch made to close in the round.
Rnd 1: Ch 5, [(3 dc, ch 2) rep ( ) 3 times, 2 dc] inside ch-4 ring, sl st in 3rd beg ch= 4 sides of 3 dc and 4 ch-2 corners

Rnd 2: Sl st in next ch, ch 5, 3 dc in first ch-2 sp, [ch 1, (3 dc, ch 2, 3 dc) in next ch-2 sp] rep [ ] 3 times, ch 1, 2 dc in first ch-2 sp, sl st in 3rd beg ch= 4 sides of 1 ch-1 sp, 4 corners of 6 dc and 1 ch-2 sp

Rnd 3: Sl st in next ch, ch 5, 3 dc in first ch-2 sp, [ch 1, 3 dc in next ch-1 sp, ch 1, (3 dc, ch 2, 3 dc) in next ch-2 sp] rep [ ] 3 times, ch 1, 3 dc in next ch-1 sp, ch 1, 2 dc in first ch-2 sp, close with sl st or invisible join in the 3rd beg ch= 4 sides of 3 dc and 2 ch-1 sp, 4 corners of 6 dc and 1 ch-2 sp
Fasten off and weave in all ends.

And that is how you crochet your classic granny. Make more rounds to make it bigger, by making (3 dc, ch 2, 3 dc) in each of the 4 corners, 3 dc in every ch-1 sp on the four sides of the square, and ch-1 spaces next to each dc-3 group on each side of the square.
You can also follow the crochet chart with symbols below.

Put this basic granny square into practice through an actual project. Check the Granny Square Clutch tutorial, where you will also learn how to make granny triangles.