It is notable for being one of the three Starter types, forming a perfectly triangular relationship with Grass and Water.
Fire-type moves are based on attacks of fire itself, and most of them can leave the status Burn. Fire types are also immune to being Burned, regardless of the type of move used that would have inflicted a Burn.
Fire Pokémon have notably fewer species compared to the other Starter types, due to a lack of natural phenomena that can be described as fire - the Slugma line, Numel line, Magmar line, Torkoal, and Volcanion are the closest representation. Some Fire-type species are based on land animals known for their predatory instincts, such as Pyroar, Arcanine and Heatmor. The Vulpix and Fennekin lines are both based on Japanese folklore linking species of fox with fire, while curiously, most generations of Fire-type starter, as well as the Ponyta, Houndour and Pansear lines, are all based on animals from the Chinese zodiac. However, there are a few Fire-type Pokémon that are based on inanimate objects, such as Rotom's Heat form and the Litwick line.
They're strong against the Bug type because it's easy to burn an insect, and it's difficult for it to survive.
They're strong against the Grass type because fire consumes plants easily, and even though the fire is extinguished, the plants are damaged heavily.
They're strong against the Ice type because fire melts ice.
They're strong against the Steel type because metal conducts heat, and fire is used to melt down metals.
They're weak against the Ground type because if sand, dirt, or mud is thrown over a fire, the fire dies out.
They're weak against the Rock type because fire is easily extinguished if rocks are thrown over it, and because rocks can withstand extreme heat from the fire.
They're weak against the Water type because water extinguishes it.
They resist the Fairy type because traditionally, fairies live in forests, and fire destroys the forests. Fire, along with steel, is also considered manmade, which is anathema to fairies. Interestingly, the Fairy type isn't weak to it.
The Dragon type resists them because, in ancient legends, dragons weren't affected by nature's principal forces (plants, water, fire and electricity). In addition, most dragons in legends breathe fire.
They resist themselves because trying to fight a fire with fire would increase the flame.
All of the final evolutions of the Fire-type starters seem to resemble or closely resemble a zodiac animal.