Solar Panels, which collect light and convert that light to DC Power, are placed on the roof, or a ground mount. DC power is what batteries produce, not what we use in our homes. Panels are placed in groups, referred to as "Strings", and high voltage DC is fed into the home.
The "Strings" are connected to a battery charge controller, which regulates the power to keep a bank of batteries charged up.
Battery banks store the energy produced from the panels, special solar batteries are used that can handle the high charge current that the solar panels produce. These battery banks are sized to provide anywhere from Hours to Days of power without sunlight to recharge them, in case of stormy days.
A Central inverter is hooked to the battery bank, and converts the DC battery power to standard household AC power for use in your home. If this inverter is tied to street side power, or a generator, it can also charge the batteries if needed during extended periods of no sun.