Smart meters are digital measuring devices that record a building's energy consumption precisely and time-resolved. Unlike analog Ferraris meters, they can automatically transmit consumption data to the grid operator, enabling accurate billing without manual readings. The Smart Meter Gateway (SMGW) forms the secure communication unit connecting meters, grid operators, and energy suppliers. Under the German Metering Point Operation Act (MsbG), installation is mandatory above certain consumption thresholds or for PV systems. Smart meters also form the basis for dynamic tariffs and intelligent control of consumers in a smart home context, supporting demand response and grid stabilization strategies.