For sewing:
* Stiche: This is the most general term for stitches.
* Nähte: This refers to seams, which are lines of stitches.
For medical purposes:
* Nähte: This is the term for stitches used to close wounds.
* Fäden: This refers to the thread used for stitching.
Examples:
* Ich habe mir den Finger genäht. (I stitched my finger.)
* Die Wunde muss genäht werden. (The wound must be stitched.)
* Die Naht ist gut verheilt. (The stitch is healing well.)
* Der Stoff hat viele Stiche. (The fabric has many stitches.)
* Die Nähte sind sehr stabil. (The seams are very sturdy.)