What is the difference between the electron configuration of Na and Na+?

The electron configuration of $\text{Na"^+}$ has one less electron, and is isoelectronic with the noble gas neon.
The electron configuration of $\text{1s"^2"2s"^2"2p"^6"3s"^1}$, or $\text{[Ne]3s"^1}$.
The electron configuration of $\text{1s"^2"2s"^2"2p"^6}$, in which the $\text{3s"^1}$ electron has been lost, and which is the electron configuration of the noble gas neon.