Burners on gas cooktops and rangetops have come a long way over the years. They can simmer so low as to melt chocolate and hold it in that melted state for hours. Yet that same burner can boil up to 4 quarts of water in a little more than 10 minutes. The cooktops available today can come in a variety of sizes and styles, differing from manufacturer to manufacturer. While different in many ways, at their core, gas burners found on cooktops and rangetops are very similar. Gas flows from a main gas valve to the burner through a venturi tube, which allows the gas to properly mix with air for clean combustion. The mixture flows into the burner where it is lit by an igniter. From this stepping off point, however, technology begins to vary.