If you are interested in solar lights, there is a good probability that you’ve wondered how they work. For the purpose of this explanation I’ll use solar garden lights as an example. There are a few components to solar lighting that you should be aware of.

1. Solar panel – A solar panel is made up of several tiny solar cells that convert the sun’s energy into electricity.  All solar garden lights will have a small solar panel on them. 
2. Charge controller circuit – This is a small electronic circuit designed to keep the solar panel from overcharging the battery. 
3.  Rechargeable battery – All solar garden lights will have some sort of a small rechargeable battery.  The best use lithium ion batteries but lithium ion technology is expensive so the majority of solar garden lights will probably use a Ni Cad rechargeable battery. 
4.  Like bulb - Many solar garden lights use LED light bulbs because they consume vary little energy.  Regular incandescent light bulbs are also used on solar garden lighting although they’re not as efficient in using the power from the battery.  Incandescent lighting is an energy hog. 
5.  Photoelectric eye – All solar garden lighting will have a photoelectric high that is sensitive to the sun.  When the sun goes down and is no longer shining on the photoelectric eye, this triggers a switch that turns the solar garden light on.  When the sun comes up in the morning, the switch is triggered again because the photoelectric eye is sensitive to sunlight and the solar garden light turns off.
6. On/Off switch -  Most, but not all solar garden lighs will have an on/off switch so that it can be turned on or off as the user desires.

There you have it.  The above mentioned items are the basic elements in any solar light.   No matter how the light is designed or for what purpose it is designed, all solar lights will have these basic elements.  Some of the elements may be configured differently depending upon the application.