Addded chaos figure and some motivation

git-tutorial.tex

@@ -21,6 +21,29 @@
 \section{Introduction}
 \label{sec:intro}
 
+Why use git, or any other version control software to keep track of
+files? In short there are at least three big reasons why you should
+version control your files, two of which are valid also if you work
+all by yourself. See Figure~\ref{fig:chaos} for an illustration of the
+first two reasons listed below:
+\begin{description}
+\item[Backups:] With version control you always have previous versions
+  of your files available, if you happen to do something stupid like
+  erasing a file. Or just regret a large edit later on.
+\item[Organization:] Knowing which copy of a project directory is up
+  to date, and which ones are not, saves a lot of time and problems.
+\item[Collaboration:] Everyone who has tried to collaborate with other
+  people by sending files, or parts of files, over email knows how
+  fragile that is.
+\end{description}
+
+\begin{figure}[h!]
+  \centering
+  \pgfimage[width=.9\textwidth]{chaos.png}
+  \caption{Typical(?) result after version control by renaming.}
+  \label{fig:chaos}
+\end{figure}
+
 \section{Git Tools}
 \label{sec:tools}
 
@@ -57,7 +80,18 @@ people.
 \subsection{Standalone Repository}
 \label{sec:standalone}
 The simplest use case is that of one single developer, one local
-repository. 
+repository. Files in a project versioned with git go through the
+following stages as you work on them, see Figure~\ref{fig:lifecycle}:
+\begin{description}
+\item[Untracked:] Git does not know anything about untracked files.
+\item[Tracked, unmodified:] Git knows about these files, and there
+  have been no changes to them since lst commit.
+\item[Tracked, modified:] Files tracked by git, there are changes made
+  to the file since last commit but git does not know whether these
+  changes should go into next commit.
+\item[Staged:] The changes made to this file will be committed next
+  time you perform a commit.
+\end{description}
 
 \begin{figure}[h!]
   \centering
@@ -289,7 +323,8 @@ To stodola.control.lth.se:work/computers/git-tutorial
   \verb|http://git-scm.com/documentation|
   or\\
   \verb|http://www.git-tower.com/files/cheatsheet/Git_Cheat_Sheet_grey.pdf|
-\item The \emph{Pro Git} book is available online: \verb|http://git-scm.com/book|
+\item The extensive \emph{Pro Git} handbook is available for free
+  online: \verb|http://git-scm.com/book|
 \end{itemize}
 
 \end{document}