<s>
An	O
actor	O
in	O
the	O
Unified	B-Language
Modeling	I-Language
Language	I-Language
(	O
UML	B-Language
)	O
"	O
specifies	O
a	O
role	O
played	O
by	O
a	O
user	O
or	O
any	O
other	O
system	O
that	O
interacts	O
with	O
the	O
subject.	O
"	O
</s>
<s>
Actors	O
do	O
not	O
necessarily	O
represent	O
specific	O
physical	O
entities	O
but	O
merely	O
particular	O
facets	O
(	O
i.e.	O
,	O
“	O
roles	O
”	O
)	O
of	O
some	O
entities	O
that	O
are	O
relevant	O
to	O
the	O
specification	O
of	O
its	O
associated	O
use	B-Architecture
cases	I-Architecture
.	O
</s>
<s>
UML	B-Language
2	I-Language
does	O
not	O
permit	O
associations	O
between	O
Actors	O
.	O
</s>
<s>
Actors	O
interact	O
with	O
use	B-Architecture
cases	I-Architecture
.	O
</s>
