Suture
Suture is a stitch used to hold the edges of a wound together so it can heal.
Think of it this way
A torn seam on a fabric sleeve works the same way. You lay both edges of the tear side by side on a flat surface. Then you push a needle and thread through both sides in small, even stitches. Each stitch pulls the two edges together and holds them flush until the fabric bonds back into one piece.
Explaining suture by grade level
When you get a deep cut, a doctor may sew it shut. The thread holds the two sides of skin close together. This helps the cut heal faster and keeps dirt out. Some stitches go side to side, and some go up and down.