two introductories slides

source/talk.tex

@@ -16,8 +16,22 @@
 \frame{\titlepage}
  
 \begin{frame}
-\frametitle{Sample frame title}
-This is a text in first frame. This is a text in first frame. This is a text in first frame.
+\frametitle{Why do we need backups?}
+Bad things can happen and do happen:
+        \begin{itemize}
+                \item You may drop your computer.
+                \item The disk may be shaken during a train trip.
+                \item The computer where you keep the only copy of your thesis
+                        may be stolen.
+                \item Or after some time it may be simply age.
+        \end{itemize}                
 \end{frame}
 
+\begin{frame}
+        \frametitle{What are backups?}
+        \begin{block}{Definition}
+                The copying and archiving of computer data so that it may be 
+                used to restore the original after a data loss event.
+        \end{block}
+\end{frame}        
 \end{document}