When I was growing up, lighters made a spark by rubbing a metal wheel across a flint (which was not really made out of flint.) Lighters like this one ignite the flame in a different way. How is the gas ignited?
Inside the lighter is a thin piece of quartz crystal. When you squeeze the trigger, you pull back a spring. Then it releases to impact the crystal. Quartz is piezoelectric, which means that under pressure, it produces an electric charge. The impact on the quartz causes a charge strong enough to produce an electric spark. That spark is hot enough to ignite the gas from the lighter.