This post is designed for classroom use in teaching children about the different parts of a racing (or road) bike. Note that here the primary distinction to identify a "road" or "racing" bike is if it has "drop bars" (though not all bikes with drop bars are racing or road bikes).
A "road bike frame:
A complete road bike.
Detail of a quick release for the wheel on a racing bike:
Front and rear quick release: note that the rear quick release is longer to accommodate the cassette for the gears:
Note the position of the quick release handle when it is closed and open.
Seat post quick release. This quick release operates just like a quick release on a wheel but it has a shorter "skewer."