Following are the components of  a typical and Complicated Photo voltaic Systems:

1. Solar Cell,Solar Panel & Solar Arrays.
2. Solar Mounting Systems
3. Solar Trackers
4. Solar Charge Controllers.
5. Solar Inverters.
6. Monitoring & Metering Systems.

Depending upon the following broad type of systems, the above components are used as per their needs:
1.Stand Alone Systems without Battery Backup.
2.Stand Alone Systems with Battery Backup.
3.Grid connected system without Backup.
4.Grid Connected System with Battery Back Up.

However, there are lot of Solar Devices, which should be understood as Solar generator only but are still not Systems, such as whole range of Products such as Solar Street Lights,Solar Blinkers,Solar Delineators and Solar Road studs e.t.c, which are designed to be used for different applications, They are classified into two categories:

1.Nocturnal Devices- Devices which work only after the daylight is not there.
2.Non Nocturnal Devices- Devices which work both during day and night.