Naphtha typicaly refers to a number of different flammable liquid mixtures of hydrocarbons, i.e. a distillation product from petroleum or coal tar boiling in a certain range and containing certain hydrocarbons, a broad term encompassing any volatile, flammable liquid hydrocarbon mixture.

Naphtha is used primarily as feedstock for producing a high octane gasoline component (via the catalytic reforming process). It is also used in the petrochemical industry for producing olefins in steam crackers and in the chemical industry for solvent (cleaning) applications.

Naphtha is a refined light distillate fraction, usually boiling below 250C,
but often with a fairly wide boiling range. Gasoline and kerosine are the
most well-known, but there are a whole range of special-purpose hydrocarbon
fractions that can be described as naphtha. The petroleum refining industry
calls the 0-100C fraction from the distillation of crude oil "light virgin
naphtha" and the 100-200C fraction " heavy virgin naphtha". The product
stream from the fluid catalytic cracker is often split into three fractions,
<105C = "light FCC naphtha", 105-160C = "intermediate FCC naphtha" and
160-200C "heavy FCC naphtha".

Naptha is a rather volatile but clean-burning fuel. it was used in the late nineteenth century for auxiliary power on basically sailing ships (suchas those used by explorers) and also some Russian submarines in World War I.

Naphta as a vebicular fuel is more or less obsolete but had considerable usage inthe late nineteenth century on (fifty fifties) as this minimized the hazard of the rigging and sails catching fire, always a hazard on a sailing ship and particulairoly an auxiliary steamer.

http://wiki.answers.com/Q/What_are_the_uses_for_the_naptha
http://stason.org/TULARC/science-engineering/chemistry/27-5-What-is-naphtha.html