<s>
In	O
optical	B-Application
disc	I-Application
authoring	I-Application
,	O
there	O
are	O
multiple	O
modes	O
for	O
recording	O
,	O
including	O
Disc-At-Once	B-Application
,	O
Track-At-Once	B-Application
,	O
and	O
Session-At-Once	O
.	O
</s>
<s>
Disc-At-Once	B-Application
(	O
DAO	O
)	O
for	O
CD-R	O
media	O
is	O
a	O
mode	O
that	O
masters	O
the	O
disc	O
contents	O
in	O
one	O
pass	O
,	O
rather	O
than	O
a	O
track	O
at	O
a	O
time	O
as	O
in	O
Track	B-Application
At	I-Application
Once	I-Application
.	O
</s>
<s>
Track-At-Once	B-Application
(	O
TAO	O
)	O
is	O
a	O
recording	O
mode	O
where	O
the	O
recording	O
laser	O
stops	O
after	O
each	O
track	O
is	O
finished	O
and	O
two	O
run-out	O
blocks	O
are	O
written	O
.	O
</s>
<s>
Disc-At-Once	B-Application
(	O
DAO	O
)	O
recording	O
for	O
DVD-R	O
media	O
is	O
a	O
mode	O
in	O
which	O
all	O
data	O
is	O
written	O
sequentially	O
to	O
the	O
disc	O
in	O
one	O
uninterrupted	O
recording	O
session	O
.	O
</s>
<s>
The	O
on-disk	O
contents	O
result	O
in	O
a	O
lead-in	O
area	O
,	O
followed	O
by	O
the	O
data	O
,	O
and	O
closed	O
by	O
a	O
lead-out	B-Application
area	O
.	O
</s>
<s>
There	O
are	O
no	O
run-out	O
blocks	O
as	O
in	O
CD-R	O
disc-at-once	B-Application
.	O
</s>
<s>
Session-At-Once	O
(	O
SAO	O
)	O
recording	O
allows	O
multiple	O
sessions	O
to	O
be	O
recorded	O
and	O
finalized	B-Application
on	O
a	O
single	O
disc	O
.	O
</s>
<s>
It	O
uses	O
the	O
Disc-At-Once	B-Application
method	O
,	O
usually	O
at	O
1x	O
,	O
but	O
some	O
recorders	O
allow	O
for	O
4x	O
and	O
8x	O
speed	O
mode	O
.	O
</s>
