The main purpose of outdoor lighting is to provide light in your yard at night. This does not have to be the sole purpose though; outdoor lighting can do much more. It can actually be a part of the landscape design in many ways. Kansas City Home and Garden detailed how outdoor lighting can be used for security, entertainment and design purposes.
Design: Lights can be used to create designs or highlight those already incorporated into the landscape. They can also be used to draw attention to special décor or focal points you want noticed.
Security: Lighting can be used to expose dark areas and entrance ways. Motions sensors can come on at any sign of movement and can even set off alarms. Security lights are helpful when you take vacation because the timers can be set to turn lights on and off as they would if you were at home.
Entertainment: Add an extra element of entertainment to your yard by using uniquely designed or colored lights. Lights can display color, be synced to music, shot in beams, and placed at the bottom of your pool.