<s>
A	O
file	B-Application
viewer	I-Application
is	O
a	O
Software	B-Application
application	I-Application
that	O
represents	O
the	O
data	O
stored	O
in	O
a	O
computer	B-Operating_System
file	I-Operating_System
in	O
a	O
human-readable	O
form	O
.	O
</s>
<s>
The	O
file	O
contents	O
are	O
formatted	O
in	O
a	O
meaningful	O
way	O
,	O
then	O
displayed	O
on	O
the	O
screen	B-Device
,	O
printed	O
out	O
,	O
or	O
read	O
aloud	O
using	O
speech	B-Application
synthesis	I-Application
.	O
</s>
<s>
File	B-Application
viewer	I-Application
applications	O
can	O
be	O
split	O
into	O
the	O
following	O
categories	O
:	O
</s>
<s>
File	B-Application
Viewer	I-Application
Only	O
applications	O
do	O
not	O
allow	O
the	O
user	O
to	O
edit	O
files	O
.	O
</s>
<s>
File	B-Application
Viewer	I-Application
and	O
Converter	O
applications	O
allow	O
both	O
viewing	O
of	O
data	O
and	O
exporting	O
data	O
in	O
a	O
different	O
file	O
format	O
or	O
copying	O
information	O
the	O
clipboard	O
.	O
</s>
<s>
File	B-Application
Viewer	I-Application
and	O
Editor	O
applications	O
allow	O
the	O
user	O
to	O
view	O
existing	O
files	O
,	O
create	O
a	O
new	O
file	O
of	O
specific	O
type	O
or	O
modify	O
the	O
content	O
of	O
an	O
existing	O
file	O
.	O
</s>
<s>
For	O
example	O
,	O
database	O
software	O
DBASE	B-Application
used	O
proprietary	O
algorithm	O
for	O
creating	O
.DBF	O
files	O
,	O
but	O
Norton	B-Application
Commander	I-Application
had	O
a	O
built-in	O
viewer	O
for	O
.DBF	O
files	O
.	O
</s>
<s>
Acrobat	B-Application
Reader	I-Application
supports	O
viewing	O
of	O
.PDF	B-Application
files	O
,	O
but	O
another	O
software	B-Application
application	I-Application
such	O
as	O
Adobe	B-Operating_System
Photoshop	I-Operating_System
,	O
LibreOffice	B-Application
or	O
Microsoft	B-Application
Word	I-Application
is	O
required	O
to	O
create	O
.PDF	B-Application
files	O
.	O
</s>
<s>
File	B-Application
viewers	I-Application
need	O
to	O
have	O
structure	O
information	O
about	O
the	O
file	O
format	O
to	O
be	O
viewed	O
in	O
order	O
to	O
handle	O
different	O
byte	O
orders	O
,	O
code	O
pages	O
or	O
newline	O
styles	O
.	O
</s>
<s>
On	O
contrary	O
,	O
media	O
file	B-Application
viewers	I-Application
,	O
such	O
as	O
Video	O
Player	O
applications	O
may	O
have	O
initially	O
very	O
small	O
number	O
of	O
file	O
formats	O
or	O
none	O
recognized	O
,	O
but	O
rely	O
on	O
video	B-Algorithm
codecs	I-Algorithm
to	O
play	O
various	O
media	O
,	O
making	O
their	O
capability	O
to	O
read	O
and	O
represent	O
media	O
file	O
data	O
to	O
the	O
user	O
expandable	O
.	O
</s>
<s>
Some	O
file	B-Application
viewer	I-Application
may	O
be	O
classified	O
as	O
filters	O
that	O
translate	O
binary	O
files	O
into	O
plain	O
text	O
(	O
e.g.	O
,	O
antiword	B-Operating_System
)	O
.	O
</s>
<s>
Image	B-Application
viewers	I-Application
display	O
graphics	O
files	O
onscreen	O
.	O
</s>
<s>
Some	O
viewers	O
such	O
as	O
IrfanView	B-Protocol
are	O
capable	O
of	O
reading	O
multiple	O
graphics	O
file	O
formats	O
but	O
some	O
such	O
as	O
JPEGview	B-Application
are	O
dedicated	O
to	O
a	O
single	O
format	O
.	O
</s>
<s>
Common	O
image	B-Application
viewer	I-Application
features	O
include	O
thumbnail	O
preview	O
and	O
creation	O
,	O
image	O
zooming	O
and	O
rotation	O
,	O
color	O
balance	O
and	O
gamma	O
correction	O
,	O
resizing	O
etc	O
.	O
</s>
<s>
A	O
web	B-Application
browser	I-Application
is	O
a	O
type	O
of	O
file	B-Application
viewer	I-Application
,	O
which	O
renders	O
HTML	B-Language
markup	O
into	O
a	O
human-friendly	O
presentation	O
.	O
</s>
<s>
Although	O
HTML	B-Language
is	O
stored	O
in	O
plain	O
text	O
files	O
,	O
viewing	O
an	O
HTML	B-Language
file	I-Language
in	O
a	O
browser	B-Application
and	O
in	O
a	O
text	B-Application
editor	I-Application
produces	O
significantly	O
different	O
results	O
.	O
</s>
<s>
Web	B-Application
browsers	I-Application
may	O
also	O
be	O
used	O
to	O
view	O
multimedia	O
files	O
such	O
as	O
images	O
,	O
videos	O
,	O
pre-formatted	O
documents	O
,	O
interactive	O
environments	O
,	O
3D	O
models	O
,	O
augmented	B-General_Concept
reality	I-General_Concept
and	O
virtual	B-Application
reality	I-Application
applets	O
etc	O
.	O
</s>
