A native born citizen is a natural born citizen.
Washington, Adams, Jefferson et al were born in the colony of America under British rule and became citizens with the adoption of the Constitution. They feared for the future when, for example, a British subject born here in the US, might have dual loyalties, hence the strict language which makes it (natural born) -a unique requirement for the POTUS and Vice Potus.
Natural born, i.e., born in the USA to American citizens. McCain and Obama are both not natural born, unless the Supremes rule differently. Could go on but you'll find it all at www.naturalborncitizen.wordpress.com.