Solar Power Sytem for home includes one or more Solar PV Modules consisting of solar cells, a charge controller which distributes power and protects the batteries and appliances from damage and at least one battery to store energy for use when the sun is not shining.
On-grid means your solar system is tied to your local utility's GRID. Being grid-tied is beneficial because you don't have to buy an expensive battery back-up system to store any excess energy.