What is hook and loop on a hat?

Answer 1

The hook and loop on a hat is the velcro at the back, where it does up, the loop is the soft furry side of the velcro and the hook is the hard,scratchy side!

Answer 2

Hook and Loop is basically the same thing as Velcro, but due to the copyright on the name Velcro, many manufacturers have opted for using the term hook and loop.