what are <label> tags?

Question

can someone explain the use of html label tags?

Answer 1

<input type="checkbox" id="mychkbx"><label for="mychkbx">click me and I check the box</label>

Try this snippet with and without the <label> tags, and you will see ;)
Accessory, the <label> and it's target don't require to be siblings ( but logically, they have to be visually close ^^ )

Answer 2

They are used to define a label for an <input> element. It is useful for the user as it allow to click on the label instead of, by example, the radio button.