A smile is the universal welcome.
Bonding is a technique to improve one's smile. A durable resin that matches your tooth's color is used. Bonding can fix/repair cracked or chipped teeth. It can help fill in a gap or spacing between separated teeth. It can be used to change the shape/appearance of teeth. It can help mask teeth that are discolored. It's also used to repair tooth decay.
Bonding is very cost-effective. It's a relatively quick procedure. Once the bonding material has been applied, the dentist uses a special ultraviolet light to quickly harden the material. After that, a little shaping and polishing and you're done!
The pros to bonding are the speed at which it can be accomplished (all in the same visit vs. multiple trips for other procedures like crowns), the inexpensive cost, and unless it is being used to fill a cavity, you most likely will not need anesthesia. The cons are that the material doesn't resist stains as well as crowns and that the materials don't last quite as long as other procedures. Talk with your dentist to determine the best course of action for your smile!