Solar Grid - Tied refers to a power system that generates electricity from solar array and it can be used directly. The stored energy is fed to utility using inverters and directly the generated energy can be used in day time. No storage options, connected to grid for direct usage.
A grid connection allow you to save money with solar panel through better efficiency rates, net metering, plus lower equipment & installation costs. Batteries & other stand alone equipments are required for fully functional off grid solar system & add costs as well as maintenance. Grid-tie solar systems are therefore generally cheaper & simpler to install. Your solar panels will often generates more electricity onto the utility grid instead of storing it themselves with batteries.