Fire is a tool of benefits and destruction in Minecraft, and players are capable of harnessing it in different ways. Minecraft players are likely familiar with tools such as the flint & steel, which can start a fire on many different blocks.
These tools are often used to activate nether portals and create things such as fireplaces using netherrack.
However, flint & steel isn't the only tool capable of making fire. For example, fire charges can be obtained or crafted using blaze powder, gunpowder, and coal/charcoal. Fire charges can operate similar to flint & steel but have additional uses that their counterpart can't claim.
Minecraft: Uses of fire charges
When used directly in Minecraft, fire charges will start a fire on the target block if possible. However, unlike flint & steel, this application will cause the fire charge to be used up immediately. This shouldn't be too much of an issue, as fire charges can be created in bulk and stacked like certain other items and blocks.
It can also prime TNT, light campfires, and activate nether portals, but is unable to force creepers to explode. This stands as only one application of fire charges, however, and there's plenty more that they're capable of.
When placed within a dispenser, fire charges can be used as a projectile. Similar to fireballs fired by ghasts, dispensers can fire charges in a straight line (though in a randomized direction based on the dispenser's placement) in a very similar form.
When the fireball makes contact with a block or entity, it will set them on fire if possible. If it strikes an entity, it can deal up to four and a half hearts' worth of damage due to being a projectile as well as being on fire.
In addition to setting things on fire or being used in dispenser-based projectile firing, fire charges are also used in two crafting recipes. When combined with gunpowder, glowstone dust, dye, and a diamond, Minecraft players can create a firework star.
In the event players don't have dyes available for the crafting recipe, they may also use lapis lazuli, bone meal, cocoa beans, or ink sacs as a substitute for the colors blue, white, brown, and black respectively.