<s>
In	O
computing	O
,	O
an	O
archive	B-Application
file	I-Application
is	O
a	O
computer	B-Operating_System
file	I-Operating_System
that	O
is	O
composed	O
of	O
one	O
or	O
more	O
files	O
along	O
with	O
metadata	O
.	O
</s>
<s>
Archive	B-Application
files	I-Application
are	O
used	O
to	O
collect	B-Application
multiple	O
data	O
files	O
together	O
into	O
a	O
single	O
file	O
for	O
easier	O
portability	B-Architecture
and	O
storage	O
,	O
or	O
simply	O
to	O
compress	B-Algorithm
files	O
to	O
use	O
less	O
storage	O
space	O
.	O
</s>
<s>
Archive	B-Application
files	I-Application
often	O
store	O
directory	B-Architecture
structures	I-Architecture
,	O
error	B-Error_Name
detection	I-Error_Name
and	I-Error_Name
correction	I-Error_Name
information	O
,	O
arbitrary	O
comments	O
,	O
and	O
sometimes	O
use	O
built-in	O
encryption	O
.	O
</s>
<s>
Archive	B-Application
files	I-Application
are	O
particularly	O
useful	O
in	O
that	O
they	O
store	O
file	B-Application
system	I-Application
data	O
and	O
metadata	O
within	O
the	O
contents	O
of	O
a	O
particular	O
file	O
,	O
and	O
thus	O
can	O
be	O
stored	O
on	O
systems	O
or	O
sent	O
over	O
channels	O
that	O
do	O
not	O
support	O
the	O
file	B-Application
system	I-Application
in	O
question	O
,	O
only	O
file	O
contents	O
–	O
examples	O
include	O
sending	O
a	O
directory	B-Architecture
structure	I-Architecture
over	O
email	O
,	O
files	O
with	O
names	O
unsupported	O
on	O
the	O
target	O
file	B-Application
system	I-Application
due	O
to	O
length	O
or	O
characters	O
,	O
and	O
retaining	O
files	O
 '	O
date	O
and	O
time	O
information	O
.	O
</s>
<s>
Additionally	O
,	O
it	O
facilitates	O
transferring	O
high	O
numbers	O
of	O
small	O
files	O
such	O
as	O
resources	O
of	O
saved	O
web	O
pages	O
,	O
since	O
a	O
container	O
file	O
is	O
transferred	O
using	O
a	O
single	O
file	O
operation	O
,	O
whereas	O
transferring	O
many	O
small	O
files	O
requires	O
the	O
computer	O
to	O
modify	O
the	O
file	B-Application
system	I-Application
structure	O
for	O
each	O
file	O
individually	O
,	O
making	O
it	O
considerably	O
slower	O
.	O
</s>
<s>
Beyond	O
archival	O
purposes	O
,	O
archive	B-Application
files	I-Application
are	O
frequently	O
used	O
for	O
packaging	O
software	O
for	O
distribution	B-Application
,	O
as	O
software	O
contents	O
are	O
often	O
naturally	O
spread	O
across	O
several	O
files	O
;	O
the	O
archive	B-Application
is	O
then	O
known	O
as	O
a	O
package	O
.	O
</s>
<s>
While	O
the	O
archival	O
file	O
format	O
is	O
the	O
same	O
,	O
there	O
are	O
additional	O
conventions	O
about	O
contents	O
,	O
such	O
as	O
requiring	O
a	O
manifest	O
file	O
,	O
and	O
the	O
resulting	O
format	O
is	O
known	O
as	O
a	O
package	B-Application
format	I-Application
.	O
</s>
<s>
Examples	O
include	O
deb	O
for	O
Debian	O
,	O
JAR	B-Language
for	O
Java	B-Language
,	O
APK	B-Application
for	O
Android	B-Application
,	O
and	O
self-extracting	B-General_Concept
Windows	B-Application
Installer	I-Application
executables	B-Application
.	O
</s>
<s>
Some	O
archive	B-Application
programs	O
have	O
self-extraction	O
,	O
self-installation	O
,	O
source	O
volume	O
and	O
medium	O
information	O
,	O
and	O
package	O
notes/description	O
.	O
</s>
<s>
The	O
file	O
extension	O
or	O
file	B-General_Concept
header	I-General_Concept
of	O
the	O
archive	B-Application
file	I-Application
are	O
indicators	O
of	O
the	O
file	O
format	O
used	O
.	O
</s>
<s>
Computer	O
archive	B-Application
files	I-Application
are	O
created	O
by	O
file	B-Application
archiver	I-Application
software	O
,	O
optical	O
disc	O
authoring	O
software	O
,	O
and	O
disk	B-Application
image	I-Application
software	O
.	O
</s>
<s>
An	O
archive	B-Application
format	O
is	O
the	O
file	O
format	O
of	O
an	O
archive	B-Application
file	I-Application
.	O
</s>
<s>
Compression	O
only	O
formats	O
only	O
compress	B-Algorithm
files	O
.	O
</s>
<s>
Multi-function	O
formats	O
can	O
store	O
metadata	O
,	O
concatenate	O
,	O
compress	B-Algorithm
,	O
encrypt	O
,	O
create	O
error	B-Error_Name
detection	I-Error_Name
and	O
recovery	O
information	O
,	O
and	O
package	O
the	O
archive	B-Application
into	O
self-extracting	B-General_Concept
and	O
self-expanding	O
files	O
.	O
</s>
<s>
Software	O
packaging	O
formats	O
are	O
used	O
to	O
create	O
software	B-Application
packages	I-Application
that	O
may	O
be	O
self-installing	O
files	O
.	O
</s>
<s>
Disk	B-Application
image	I-Application
formats	O
are	O
used	O
to	O
create	O
disk	B-Application
images	I-Application
of	O
mass	O
storage	O
volumes	O
.	O
</s>
<s>
Filename	O
extensions	O
used	O
to	O
distinguish	O
different	O
types	O
of	O
archives	O
include	O
zip	B-General_Concept
,	O
rar	O
,	O
7z	O
,	O
and	O
tar	B-Application
,	O
the	O
first	O
of	O
which	O
is	O
the	O
most	O
widely	O
implemented	O
.	O
</s>
<s>
Java	B-Language
also	O
introduced	O
a	O
whole	O
family	O
of	O
archive	B-Application
extensions	O
such	O
as	O
jar	B-Language
and	O
war	B-Language
(	O
j	O
is	O
for	O
Java	B-Language
and	O
w	O
is	O
for	O
web	O
)	O
.	O
</s>
<s>
Archive	B-Application
files	I-Application
often	O
include	O
parity	B-Error_Name
checks	I-Error_Name
and	O
other	O
checksums	B-Algorithm
for	O
error	B-Error_Name
detection	I-Error_Name
,	O
for	O
instance	O
zip	B-General_Concept
files	I-General_Concept
use	O
a	O
cyclic	O
redundancy	O
check	O
(	O
CRC	O
)	O
.	O
</s>
<s>
RAR	O
archives	O
may	O
include	O
additional	O
error	B-Error_Name
correction	I-Error_Name
data	O
(	O
called	O
recovery	O
records	O
)	O
.	O
</s>
<s>
Archive	B-Application
files	I-Application
that	O
do	O
not	O
natively	O
support	O
recovery	O
records	O
can	O
use	O
separate	O
parchive	B-General_Concept
(	O
PAR	B-General_Concept
)	O
files	O
that	O
allows	O
for	O
additional	O
error	B-Error_Name
correction	I-Error_Name
and	O
recovery	O
of	O
missing	O
files	O
in	O
a	O
multi-file	O
archive	O
.	O
</s>
