Azimuthal quantum number ( l ) is also called subsidiary quantum number, denoted by 1 $[\ell=0,1,2,3, \ldots(\mathrm{n}-1)]$
It describes the shape of orbital occupied by the electron.
\begin{array}{ccl}
\hline Value of \boldsymbol{l} & Subshell notation & Shape of orbital \\
\hline 0 & s & Spherical \\
\hline 1 & \rho & Dumb-bell \\
\hline 2 & d except d z^2 & Double dumb-bell \\
\hline 3 & f & Complex \\
\hline
\end{array}