\section{Step-by-step reveals}

% Each click shows the next step, in the PDF (one page per step) and HTML.
% Overlay specifications say on which steps something is shown:
%   \item<2->                  an item from step 2 on (\begin{itemize}[<+->]: one per item)
%   \only<2>{...}              only on step 2, takes no space otherwise
%   \uncover<3->{...}          from step 3, keeps its space while hidden
%   \alt<4>{on 4}{otherwise}   different content on step 4
% Shapes, tasks and studies take them too (\shape<2->, \task<2->, \study<2->).
\begin{frame}{Overlay specifications}
  \begin{itemize}
    \item Shown from the start
    \item<2-> \cmd{item<2->}: from step 2
    \item<3-> \cmd{item<3->}: from step 3
  \end{itemize}
  \only<2>{\cmd{only<2>}: this line is there on step 2 only.}

  \uncover<3->{\cmd{uncover<3->}: from step 3; its space is kept before.}

  \alt<4>{\textcolor{red}{\cmd{alt<4>}: the step-4 version.}}{\cmd{alt<4>}: the version on the other steps.}
\end{frame}

% \pause: everything after it appears on the next step.
\begin{frame}{\cmd{pause}}
  \begin{itemize}
    \item First point
    \pause
    \item Appears after one click
    \pause
    \item And this after another
  \end{itemize}
\end{frame}