referencing an image in latex code example

Example 1: include image latex

\documentclass{article}

\usepackage{graphicx}

\begin{document}

\begin{figure}
  \includegraphics[width=\linewidth]{boat.jpg}
  \caption{A boat.}
  \label{fig:boat1}
\end{figure}

Figure \ref{fig:boat1} shows a boat.

\end{document}

Example 2: figure reference latex

\ref{marker}
This prints the number assigned to the object labeled by marker