# What is the difference between Big O and asymptotic notation?

Are the two interchangeable or is there a difference?

Bachmann–Landau notation or asymptotic notation is collection of notations one of which is Big-$$O$$. So they are not interchangeable, because as asymptotic notation also is known little-$$o$$, big-$$\Omega$$, big-$$\Theta$$ etc.
Historically this symbol was introduced by German mathematician Paul Bachmann and then adopted by German number theoretician Edmund Landau and American mathematician L.E. Dickson . Big-$$O$$ was shorthand for function rate of growth, which is called its order.