@item \e$B%P%C%/%(%s%I\e(B (back end)
@cindex back end
-Gnus \e$B$O%K%e!<%9$H%a!<%k$NN>J}$N$$$m$$$m$J%P%C%/%(%s%I$,M?$($?5-;v$rF@$^\e(B
-\e$B$9!#\e(BGnus \e$B$O!"$$$o$f$k2<$K2#$?$o$C$F$$$k%a%G%#%"$r07$&;v$O$7$^$;$s\e(B---\e$B$3$l\e(B
-\e$B$O$9$Y$F%P%C%/%(%s%I$K$h$C$F$J$5$l$^$9!#\e(B
+gnus \e$B$O%a!<%k$H%K%e!<%9$,$[$H$s$IF1$8$@$H$_$J$7$^$9!#K\Ev$K!#0c$$$O<B:]\e(B
+\e$B$N5-;v$K$I$N$h$&$K%"%/%;%9$9$k$+$@$1$G$9!#%a!<%k%a%C%;!<%8$O%m!<%+%k%G%#\e(B
+\e$B%9%/$N%U%!%$%k$+$iFI$a$k$N$KBP$7$F!"%K%e!<%95-;v$O0lHL$K\e(B NNTP \e$B%W%m%H%3%k\e(B
+\e$B$G<hF@$7$^$9!#\e(Bgnus \e$B$NFbIt9=B$$O!"$=$l$i$N$?$a$K\e(B `\e$B%U%m%s%H%(%s%I\e(B' \e$B$H?t!9\e(B
+\e$B$N\e(B `\e$B%P%C%/%(%s%I\e(B' \e$B$+$i@.$jN)$C$F$$$^$9!#FbItE*$K!"$"$J$?$,%0%k!<%W$KF~\e(B
+\e$B$k\e(B (\e$B$=$&!"\e(B@key{RET} \e$B$r$?$?$/\e(B) \e$B$H$-!"$=$N$?$a$K\e(B gnus \e$B$N%U%m%s%H%(%s%I$N5!\e(B
+\e$BG=$r8F$S=P$7$^$9!#%U%m%s%H%(%s%I$O$=$3$G%P%C%/%(%s%I$K!V\e(Bfoo \e$B%0%k!<%W$N5-\e(B
+\e$B;v$N%j%9%H$r$/$l!W$H$+!V\e(B4711 \e$BHV$N5-;v$r8+$;$F$h!W$H\e(B `\e$BOC$9\e(B' \e$B$N$G$9!#\e(B
+
+\e$B$=$&$$$&$o$1$G!"%P%C%/%(%s%I$O<g$K%W%m%H%3%k$+%U%!%$%k$N7A<0$H%G%#%l%/%H\e(B
+\e$B%j$NG[CV$rDj5A$7$^$9!#A0<T$O\e(B @code{nntp} \e$B%P%C%/%(%s%I$,\e(B NNTP \e$B$G%K%e!<%9\e(B
+\e$B$K%"%/%;%9$7$?$j\e(B @code{nnimap} \e$B%P%C%/%(%s%I$,\e(B IMAP \e$B$G%a!<%k$K%"%/%;%9$9\e(B
+\e$B$k$3$H$r;X$7$^$9!#$^$?!"8e<T$O\e(B @code{nnspool} \e$B%P%C%/%(%s%I$,6&DL$N\e(B `\e$B%9%W!<\e(B
+\e$B%k%G%#%l%/%H%j\e(B' \e$B7A<0$K%"%/%;%9$7$?$j!"$=$l$H$H$F$b$h$/;w$F\e(B @code{nnml}
+\e$B%P%C%/%(%s%I$,%U%!%$%k$N7A<0$H%G%#%l%/%H%j$NG[CV$K$h$C$F%a!<%k$K%"%/%;%9\e(B
+\e$B$9$k$3$H$r;X$7$^$9!#\e(B
+
+gnus \e$B$O4pK\E*$J%a%G%#%"$r07$$$^$;$s!#$9$Y$F$O%P%C%/%(%s%I$K$h$C$F9T$J$o\e(B
+\e$B$l$k$H8@$&$3$H$,$G$-$^$9!#%P%C%/%(%s%I$O5-;v$K%"%/%;%9$9$k$?$a$N5!G=$N=8\e(B
+\e$B@.$G$9!#\e(B
+
+\e$B$7$+$7!"\e(B`\e$B%P%C%/%(%s%I\e(B' \e$B$H$$$&MQ8l$O$7$P$7$P\e(B `\e$B%5!<%P!<\e(B' \e$B$H$$$&0UL#$G$b;H\e(B
+\e$B$o$l$F$-$^$7$?!#$=$7$F\e(B `\e$BA*BrJ}K!\e(B' (`select method') \e$B$bF1$80UL#$G;H$&$3$H\e(B
+\e$B$,$G$-$^$9!#$+$h$&$K!"\e(BGnus \e$B$NMQ8l$O$H$F$b:.Mp$7$F$$$^$9!#\e(B
@item \e$B4pK\\e(B (native)
@cindex native
@code{nnmaildir}.
For configuring expiry and other things, @code{nnmaildir} uses group
-parameters slightly different from those of other mail backends.
+parameters slightly different from those of other mail back ends.
@code{nnmaildir} uses a significant amount of memory to speed things up.
(It keeps in memory some of the things that @code{nnml} stores in files
would) to make it use less memory.
Startup and shutdown are likely to be slower with @code{nnmaildir} than
-with other backends. Everything in between is likely to be faster,
+with other back ends. Everything in between is likely to be faster,
depending in part on your filesystem.
@code{nnmaildir} does not use @code{nnoo}, so you cannot use @code{nnoo}
-to write an @code{nnmaildir}-derived backend.
+to write an @code{nnmaildir}-derived back end.
@end table
@item back end
@cindex back end
-Gnus gets fed articles from a number of back ends, both news and mail
-back ends. Gnus does not handle the underlying media, so to speak---this
-is all done by the back ends.
+Gnus considers mail and news to be mostly the same, really. The only
+difference is how to access the actual articles. News articles are
+commonly fetched via the protocol NNTP, whereas mail messages could be
+read from a file on the local disk. The internal architecture of Gnus
+thus comprises a `front end' and a number of `back ends'. Internally,
+when you enter a group (by hitting @key{RET}, say), you thereby invoke
+a function in the front end in Gnus. The front end then `talks' to a
+back end and says things like ``Give me the list of articles in the foo
+group'' or ``Show me article number 4711''.
+
+So a back end mainly defines either a protocol (the @code{nntp} back end
+accesses news via NNTP, the @code{nnimap} back end accesses mail via
+IMAP) or a file format and directory layout (the @code{nnspool} back end
+accesses news via the common `spool directory' format, the @code{nnml}
+back end access mail via a file format and directory layout that's
+quite similar).
+
+Gnus does not handle the underlying media, so to speak---this is all
+done by the back ends. A back end is a collection of functions to
+access the articles.
+
+However, sometimes the term `back end' is also used where `server'
+would have been more appropriate. And then there is the term `select
+method' which can mean either. The Gnus terminology can be quite
+confusing.
@item native
@cindex native