<s>
Each	O
XML	B-Protocol
document	I-Protocol
has	O
exactly	O
one	O
single	O
root	B-Language
element	I-Language
.	O
</s>
<s>
ROOT	B-Language
elements	I-Language
are	O
also	O
called	O
document	B-Language
elements	I-Language
.	O
</s>
<s>
In	O
HTML	B-Language
,	O
the	O
root	B-Language
element	I-Language
is	O
the	O
<html>	O
element	O
.	O
</s>
<s>
The	O
World	O
Wide	O
Web	O
Consortium	O
defines	O
not	O
only	O
the	O
specifications	O
for	O
XML	B-Protocol
itself	O
,	O
but	O
also	O
the	B-General_Concept
DOM	I-General_Concept
,	O
which	O
is	O
a	O
platform	O
-	O
and	O
language-independent	O
standard	O
object	O
model	O
for	O
representing	O
XML	B-Protocol
documents	I-Protocol
.	O
</s>
<s>
DOM	B-General_Concept
Level	O
1	O
defines	O
,	O
for	O
every	O
XML	B-Protocol
document	I-Protocol
,	O
an	O
object	O
representation	O
of	O
the	O
document	O
itself	O
and	O
an	O
attribute	B-Language
or	I-Language
property	I-Language
on	O
the	O
document	O
called	O
documentElement	O
.	O
</s>
<s>
This	O
property	O
provides	O
access	O
to	O
an	O
object	O
of	O
type	O
element	O
which	O
directly	O
represents	O
the	O
root	B-Language
element	I-Language
of	O
the	O
document	O
.	O
</s>
<s>
There	O
can	O
be	O
other	O
XML	B-Protocol
nodes	O
outside	O
of	O
the	O
root	B-Language
element	I-Language
.	O
</s>
<s>
In	O
particular	O
,	O
the	O
root	B-Language
element	I-Language
may	O
be	O
preceded	O
by	O
a	O
prolog	O
,	O
which	O
itself	O
may	O
consist	O
of	O
an	O
XML	B-Protocol
declaration	O
,	O
optional	O
comments	O
,	O
processing	B-Language
instructions	I-Language
and	O
whitespace	O
,	O
followed	O
by	O
an	O
optional	O
DOCTYPE	O
declaration	O
and	O
more	O
optional	O
comments	O
,	O
processing	B-Language
instructions	I-Language
and	O
whitespace	O
.	O
</s>
<s>
After	O
the	O
root	B-Language
element	I-Language
,	O
there	O
may	O
be	O
further	O
optional	O
comments	O
,	O
processing	B-Language
instructions	I-Language
and	O
whitespace	O
within	O
the	O
document	O
.	O
</s>
<s>
Within	O
the	O
root	B-Language
element	I-Language
,	O
apart	O
from	O
any	O
number	O
of	O
attributes	O
and	O
other	O
elements	O
,	O
there	O
may	O
also	O
be	O
more	O
optional	O
text	O
,	O
comments	O
,	O
processing	B-Language
instructions	I-Language
and	O
whitespace	O
.	O
</s>
<s>
A	O
more	O
expanded	O
example	O
of	O
an	O
XML	B-Protocol
document	I-Protocol
follows	O
,	O
demonstrating	O
some	O
of	O
these	O
extra	O
nodes	O
along	O
with	O
a	O
single	O
rootElement	O
element	O
.	O
</s>
