During the day solar modules capture the sun's energy and convert it to electricity using photovoltaic (PV) cells.
The charge controller or energy regulator prevents overcharge which results in out-gassing of the batteries, as well as keeping electrical storage in the batteries from discharging to the solar modules at night.
Batteries store the solar power generated and discharge the power as needed. The battery bank consists of one or more solar deep cycle type batteries. The capacity and type of battery needed is specific to your type of application.
The inverter changes the DC solar power from your battery bank into useable 240 volt AC electricity which is the most common type used by most household appliances and lighting.