The different ways crochet stitches
When you crochet it is very important how the stitches joined to stitches of the previous row. Depends on it how will look a finished fabric.
At first, let's look at the anatomy of a crochet stitch. On the picture below you can see that the stitch consists of: a front loop (red), a back loop (blue), a top of stitch (front and back loops together), a post (brown) and a space between stitches (green).
The anatomy of a crochet stitch
There are five ways to insert a hook in the stitch: under front and back loops, under front loop only, under back loop only, in space between stitches and in post of stitch. And so, let us consider in detail each method.
Method 1 - under Front and Back Loops (recommended way)
This method also called "under both loops" or "in both loops". It is as follows: when you work you insert the crochet hook under both front and back loops of the previous row.
Insertion under both Front and Back Loops
Method 2 - under Front Loop only
As the name implies, the crochet hook is inserted under the loop, which is located closer to you.
Insertion under Front Loop only
Method 3 - under Back Loop only
In this case the crochet hook is inserted under the loop, which is located further away from you.
Insertion under Back Loop only
Method 4 - in space between stitches
In this case the crochet hook isn't inserted in the loop. The hook is inserted in the space between stitches of the previous row, or under the arch formed by the chain stitches.
Insertion in Space between Stitches
Method 5 - in post of stitch
You may have noticed when you make stitches with ways, which are described above, the stitches of the next row is slightly shifted relative to the stitches of the previous row. In some cases, such as when crochet in the round, it would be desirable to avoid. In this case, use the method of crocheting "in post of stitch". The crochet hook is inserted the in post of stitch (brown dot in the picture).
Insertion in Post of Stitch