How are ‘sticky ends’ formed on a DNA strand? Why are they

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

Restriction enzymes cut the strands of the DNA, a little away from the centre of the palindromic sites, but - between the same two bases on opposite strands. This leaves sticky single stranded position at the ends. These overhanging stretches are called ‘sticky ends’. These are named so because they form hydrogen bonds with their complementary cut counter parts.