lfs-book-zh_CN/appendixa/gcc-desc.sgml

<sect2>
<title>Contents</title>

<para>
The GCC package contains compilers, preprocessors and the GNU C++
Library.
</para>

</sect2>

<sect2><title>Description</title>

<sect3><title>Compiler</title>

<para>
A compiler translates source code in text format to a format
that a computer understands. After a source code file is compiled into
an object file, a linker will create an executable file from one or more
of these compiler generated object files.
</para>

</sect3>

<sect3><title>Pre-processor</title>

<para>
A pre-processor pre-processes a source file, such as including
the contents of header files into the source file. You generally don't
do this yourself to save yourself a lot of time. You just insert a line
like #include &lt;filename&gt;. The pre-processor file insert the
contents of that file into the source file. That's one of the things a
pre-processor does.
</para>

</sect3>

<sect3><title>C++ Library</title>

<para>
The C++ library is used by C++ programs. The C++ library contains
functions that are frequently used in C++ programs. This way the
programmer doesn't have to write certain functions (such as writing a
string of text to the screen) from scratch every time he creates a
program.
</para>

</sect3>

</sect2>