For hundreds of years, golfers used a small mound of sand to tee their balls at the start of each hole. The first artificial tees appeared in the late 1880s, but the peg style we are familiar with today didn't become popular until the Reddy Tee came on the market in the 1920s.
"A tee is a device designed to raise the ball off the ground. It must not be longer than 4 inches and it must not be designed or manufactured in such a way that it could indicate the line of play or influence the movement of the ball," according to the USGA Rules of Golf.
Golf tees are available in sizes from 1 1/2 inches long up to the legal limit of 4 inches. Longer tees are available, but cannot be used for tournament play. Sizes vary by manufacturer, but the two most common sizes are 2 3/4 inches and 3 1/4 inches.
Tees include the standard wooden peg with inverted cone top, and similar product made from plastic or biodegradable material. Newer products include the Brush Tee--you literally tee the ball on a brush attached to a peg--and several brands that have little fingers or prongs that hold the tee.
While the standard wooden tee makes no claims other than to hold your ball, the newer products are all designed to reduce contact with the ball. The manufacturers claim this reduced friction results in more distance and accuracy.