Light, kindle, ignite, fire basically mean to set something burning or on fire.
Light (see also ILLUMINATE ), when it takes as its subject the agent or agency, usually implies such an end of the action as illumination.
Kindle often connotes difficulty or slowness in setting combustible materials (as wood, straw, or paper) afire; it is therefore the appropriate word when what is to burn requires special preparation or does not at once burst into flame.
Ignite is not only much more common in technical than in popular use but usually shows a difference in meaning. In technical use ignite sometimes implies heating of a substance until it glows or becomes incandescent, but it more often implies the placing of a small flame or spark (as an electric spark) in direct or indirect contact with a flammable substance (as gasoline, fuel oil, or gunpowder) so as to produce its combustion. In more general use, ignite varies little from kindle except in being more frequently employed in reference to explosives or highly flammable substances.
Fire suggests blazing and rapid combustion of what is set on fire; it is typically used in respect to something that lights easily and burns fiercely. All of these words have extended use.
Light in such use is purely a figure of speech while kindle implies an exciting, arousing, or stimulating and ignite implies a stirring up into activity.
Fire implies an inspiring with strong passion, ardent desire, or intense zeal and is usually chosen when the agent or agency enables or induces energetic activity.