The solar panels generate DC (direct current – like a battery) electricity, which is then converted in an inverter to AC (alternating current – like the electricity in your domestic socket).
Solar PV systems are rated in kilowatts (kW). A 1kW solar PV system would require 3 or 4 solar panels on your roof.
Any excess electricity produced can be stored in a battery, or other storage solution like your hot water immersion tank. It can also be exported from your house into the electrical network on your street.