Fire

Something is ablaze if it is on fire, burning brightly.

Alight can have many different meanings.
It might mean something that is on fire. It might also mean you are getting off something after it has stopped moving, like a horse or a train. It could also mean you are coming onto something after a flight, as in "see the bird alight on that branch".

Ashes are the black and grey residue that is left after a fire. Ash is also thrown out in large quantities from volcanoes. Some ash, called charcoal, can be used to draw with.

Something is burning if it is on fire. Many things can be burnt, but wood, coal and paper are the most common things to burn.

A campfire is a small outdoor fire that you build when you are out on a camping trip. People build campfires to keep warm and to cook on.

You char something by burning it slightly, so it becomes charred.

Embers are small pieces of wood or coal in a fire that are not actively burning but are still glowing and hot. Hot embers can be used to start a dying fire up again, or can set a house on fire if they fall out of a fireplace and land on flammable paper or fabric.

When something is burning, it is said to be on fire. Flames can be different colours depending on what is burning and how hot it is. Fire is very hot and bright, and people light fires in their houses to keep warm.
When a fire is out of control it can be extremely dangerous, such as a forest fire.
When something burns it gives off gas and particles as smoke. It gives off heat because burning is an exothermic reaction, which means it creates heat as it happens. Some things like boiling water are the opposite, and need heat to happen.

A flame is a small part of a fire. You typically see a flame burning on a candle or when you light a match.

You ignite something when you set it on fire. The picture is of the gas in a cigarette lighter igniting.