Q:

What do the $j$ and $m$ stand for in $|j,m\rangle$ for angular momentum in quantum mechanics?

I'm assuming it is a jth state with m value as total angular momentum?

A:

The states $|j,m\rangle$ are simultaneous eigenstates of the total angular momentum squared operator $\mathbf J^2$ and the $z$-component of the total angular momentum operator $J_z$.  The letter $j$ is related to the eigenvalue of the operator $\mathbf J^2$, while the letter $m$ gives the eigenvalue of the operator $J_z$. Specifically
$$
  \mathbf J^2|j,m\rangle =\hbar^2 j(j+1)|j,m\rangle, \qquad J_z|j,m\rangle = \hbar \,m|j,m\rangle 
$$
Given these considerations, $j$ is called the total angular momentum quantum number.
Hope that helps!  Let me know if you'd like more details.
Cheers!

