An on-grid system is a solar power system that is directly connected to the main electricity grid. The electricity generated by the solar panels is first used to power the home, and any surplus is sent to the grid.
An off-grid system is completely independent of the electricity grid. The power generated by solar panels is stored in batteries and used as needed, especially at night or during cloudy weather.
A hybrid system combines the features of both on-grid and off-grid systems. The solar power generated is used to run the appliances, charge the battery, and any extra power can be sent to the grid.