A single button triggers electric arcs that start the fire.
Indeed, some older gas stoves have an even simpler “pilot light” design that does not require that the stove be electrically powered. This has certain disadvantages (what if the pilot light goes out and small amounts of gas continue to leak into your apartment?—but this is not as bad as it sounds unless the problem remains un-fixed for an extended period of time), but also some notable advantages (stove can be operated even if the power is out; no electrical/electronic components, and thus fewer points of possible breakdown).
Indeed, some older gas stoves have an even simpler “pilot light” design that does not require that the stove be electrically powered. This has certain disadvantages (what if the pilot light goes out and small amounts of gas continue to leak into your apartment?—but this is not as bad as it sounds unless the problem remains un-fixed for an extended period of time), but also some notable advantages (stove can be operated even if the power is out; no electrical/electronic components, and thus fewer points of possible breakdown).
Or just keep a piezoelectric lighter.