How do you make fire in mine craft?

Answer 1

With gravel, get flint from it by hitting it. If it doesn't work first and gravel appears, try again until you get flint. Then, from iron ore, smelt it into an Ingot and craft it with flint and there you will have flint and steel. So right-click the square to set fire, left-click to put out the fire. (NOTE: fire can spread rapidly)

With a fire charge you can also do this, but flint and steel have more Effects