<s>
An	O
advertising	B-Operating_System
ID	I-Operating_System
is	O
a	O
unique	O
user	O
ID	O
assigned	O
to	O
a	O
mobile	O
device	O
(	O
smart	O
phone	O
,	O
tablet	B-Device
computer	I-Device
)	O
,	O
or	O
operating	O
environment	O
,	O
to	O
help	O
advertising	O
services	O
personalize	O
their	O
offers	O
.	O
</s>
<s>
Apple	O
calls	O
their	O
advertising	B-Operating_System
ID	I-Operating_System
the	O
"	O
Identifier	B-Operating_System
for	I-Operating_System
Advertisers	I-Operating_System
"	O
(	O
IDFA	O
)	O
.	O
</s>
<s>
Google	O
calls	O
their	O
"	O
Google	O
Advertising	B-Operating_System
ID	I-Operating_System
"	O
(	O
AAID	O
)	O
.	O
</s>
<s>
Microsoft	O
uses	O
a	O
similar	O
technology	O
,	O
also	O
called	O
Advertising	B-Operating_System
ID	I-Operating_System
,	O
that	O
is	O
generated	O
for	O
each	O
device	O
and	O
user	O
.	O
</s>
