Use: The square knot is used for joining small lines of equal size, reefing sail, tying lashings, tying in battens.

Not Used: Where there is a great deal of pull on the line, because knot will tighten and be very difficult to untie.

Step 1: Hold one rope in each hand. Now cross left over right, and
Step 2: ... right over left. The knot has a "square" look to it.