lfs-book/appendixa/sed-desc.xml

<sect2>
<title>Contents</title>

<para>
The Sed package contains the sed program.
</para>

</sect2>

<sect2><title>Description</title>

<para>
sed is a stream editor. A stream editor is used to perform basic text 
transformations on an input stream (a file or input from a pipeline).
</para>

</sect2>