<s>
Contacts	O
is	O
a	O
computerized	O
address	B-Operating_System
book	I-Operating_System
included	O
with	O
the	O
Apple	O
operating	O
systems	O
iOS	B-Application
,	O
iPadOS	B-Operating_System
,	O
watchOS	B-Device
and	O
macOS	B-Application
,	O
previously	O
Mac	B-Application
OS	I-Application
X	O
and	O
OS	O
X	O
.	O
</s>
<s>
It	O
includes	O
various	O
cloud	B-General_Concept
synchronization	I-General_Concept
capabilities	O
and	O
integrates	O
with	O
other	O
Apple	O
applications	O
and	O
features	O
,	O
including	O
iMessage	O
,	O
FaceTime	B-Operating_System
and	O
the	O
iCloud	B-Application
service	O
(	O
and	O
previously	O
its	O
predecessor	O
MobileMe	B-Application
)	O
.	O
</s>
<s>
An	O
application	O
known	O
as	O
Address	B-Operating_System
Book	I-Operating_System
was	O
included	O
with	O
Mac	B-Application
OS	I-Application
X	O
from	O
its	O
release	O
in	O
2001	O
and	O
in	O
preceding	O
beta	O
versions	O
.	O
</s>
<s>
Address	B-Operating_System
Book	I-Operating_System
was	O
rewritten	O
for	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
Jaguar	I-Operating_System
(	O
2002	O
)	O
and	O
as	O
of	O
2020	O
has	O
remained	O
in	O
roughly	O
the	O
same	O
form	O
ever	O
since	O
.	O
</s>
<s>
The	O
iPhone	B-Device
also	O
included	O
contacts	O
storage	O
from	O
its	O
release	O
,	O
which	O
starting	O
from	O
iPhone	B-Operating_System
OS	I-Operating_System
2	I-Operating_System
(	O
2008	O
)	O
was	O
also	O
broken	O
out	O
into	O
a	O
standalone	O
application	O
.	O
</s>
<s>
In	O
2010	O
,	O
the	O
iPad	B-Device
with	O
iOS	B-Operating_System
3.2	I-Operating_System
introduced	O
a	O
new	O
two-pane	O
contacts	O
app	O
,	O
featuring	O
the	O
skeuomorphic	O
design	O
style	O
popular	O
with	O
Apple	O
around	O
this	O
time	O
under	O
the	O
leadership	O
of	O
Scott	O
Forstall	O
.	O
</s>
<s>
OS	B-Application
X	I-Application
Lion	I-Application
(	O
2011	O
)	O
featured	O
a	O
redesigned	O
Address	B-Operating_System
Book	I-Operating_System
application	O
in	O
the	O
style	O
of	O
the	O
iPad	B-Device
Contacts	O
app	O
,	O
also	O
in	O
a	O
two-pane	O
design	O
.	O
</s>
<s>
In	O
2012	O
with	O
OS	B-Operating_System
X	I-Operating_System
Mountain	I-Operating_System
Lion	I-Operating_System
it	O
returned	O
to	O
a	O
three-pane	O
design	O
and	O
changed	O
names	O
to	O
match	O
iOS	B-Application
.	O
</s>
<s>
The	O
following	O
year	O
,	O
both	O
versions	O
of	O
Contacts	O
switched	O
with	O
their	O
parent	O
operating	O
systems	O
to	O
a	O
more	O
flat	B-Application
design	I-Application
style	O
,	O
a	O
change	O
attributed	O
to	O
Forstall	O
's	O
departure	O
from	O
Apple	O
in	O
the	O
autumn	O
of	O
2012	O
.	O
</s>
<s>
In	O
2013	O
iOS	B-Application
Contacts	O
switched	O
to	O
the	O
new	O
UI	O
along	O
with	O
the	O
whole	O
of	O
iOS	B-Operating_System
7	I-Operating_System
,	O
while	O
with	O
OS	B-Operating_System
X	I-Operating_System
Mavericks	I-Operating_System
the	O
skeuomorphic	O
design	O
was	O
removed	O
leaving	O
a	O
basic	O
UI	O
.	O
</s>
<s>
With	O
OS	B-Device
X	I-Device
Yosemite	I-Device
(	O
2014	O
)	O
the	O
OS	O
X	O
Contacts	O
app	O
switched	O
along	O
with	O
the	O
rest	O
of	O
the	O
operating	O
system	O
to	O
the	O
iOS	O
7-style	O
UI	O
.	O
</s>
<s>
In	O
2021	O
,	O
Apple	O
introduced	O
Contacts	O
to	O
Apple	B-Device
Watch	I-Device
in	O
watchOS	B-Device
8	O
.	O
</s>
<s>
Synchronizes	O
with	O
Yahoo	B-Application
!	I-Application
</s>
<s>
In	O
releases	O
prior	O
to	O
Lion	B-Application
,	O
in	O
View	O
Card	O
and	O
Column	O
,	O
the	O
Contacts	O
window	O
is	O
divided	O
into	O
three	O
panes	O
.	O
</s>
<s>
Yahoo	B-Application
!	I-Application
</s>
<s>
Contacts	O
can	O
search	O
LDAP	B-Protocol
(	O
network	O
)	O
directories	O
.	O
</s>
<s>
Users	O
customize	O
these	O
in	O
the	O
LDAP	B-Protocol
tab	O
of	O
the	O
preferences	O
.	O
</s>
