There is no difference in meaning and little or no difference in use.
Chemicals, gases or cloth materials that are flammable / inflammable catch fire and burn easily. Perhaps, in usage, cloth materials are usually described as inflammable. So we might say: 'The material from which these car seats are made is highly inflammable. And conversely, certain gases or chemicals may be thought of as flammable. So we might say: 'Aircraft fuel is highly flammable'. But there are no hard and fast patterns.
What is the difference between flammable and inflammable?
Both words mean the same thing, i.e. that something can be set on fire.
The reason for the confusion comes from people thinking that the prefix in- of inflammable is the Latin negative prefix in- (which is commonly used in English, e.g. indecent). In actual fact, in this case it is derived from the Latin preposition in. It's easier to think about it with the word inflame. If you can inflame something, it is inflammable (inflame-able).
In most cases, it is better to just use flammable to avoid confusion and accidents.