{subcaption} is a package for typesetting captions of {subfloats}.
subcaption is a package for typesetting captions of subfloats.
Here's an example demonstrating the basic use of subcaption.
\documentclass{article}
\usepackage{graphicx}
\usepackage{caption}
\usepackage{subcaption}
\begin{document}
\begin{figure}
\centering
\begin{subfigure}[b]{0.4\textwidth}
\includegraphics[width=\textwidth]{img1}
\caption{First image}
\end{subfigure}
\qquad
\begin{subfigure}[b]{0.4\textwidth}
\includegraphics[width=\textwidth]{img2}
\caption{Second Image}
\label{second}
\end{subfigure}
\caption{Some test images}
\end{figure}
\end{document}
