How are 'sticky ends' formed on a DNA strand? Why are they so called ?

Explanation

Sticky ends are produced by restriction enzymes. These enzymes cut the strand of DNA a little away from the center of the palindrome sites but between the same two bases on the opposite strands.
This leaves single strand portions at the ends. There are overhanging stretches called 'sticky ends' on each strand.
These are called sticky ends because they form hydrogen bonds with their complementary cut counterparts. This stickness of the ends facilitates the action of the enzyme DNA ligase.