<s>
An	O
application	B-Architecture
domain	I-Architecture
is	O
a	O
mechanism	O
(	O
similar	O
to	O
a	O
process	B-Operating_System
in	O
an	O
operating	B-General_Concept
system	I-General_Concept
)	O
used	O
within	O
the	O
Common	O
Language	O
Infrastructure	O
(	O
CLI	O
)	O
to	O
isolate	O
executed	O
software	B-Application
applications	I-Application
from	O
one	O
another	O
so	O
that	O
they	O
do	O
not	O
affect	O
each	O
other	O
.	O
</s>
<s>
Each	O
application	B-Architecture
domain	I-Architecture
has	O
its	O
own	O
virtual	B-General_Concept
address	I-General_Concept
space	I-General_Concept
which	O
scopes	O
the	O
resources	O
for	O
the	O
application	B-Architecture
domain	I-Architecture
using	O
that	O
address	B-General_Concept
space	I-General_Concept
.	O
</s>
<s>
Creating	O
multiple	O
application	B-Architecture
domains	I-Architecture
in	O
the	O
same	O
process	B-Operating_System
is	O
not	O
possible	O
in	O
.NET	O
Core	O
and	O
.NET	O
5+	O
.	O
</s>
<s>
A	O
CLI	O
application	B-Architecture
domain	I-Architecture
is	O
contained	O
within	O
an	O
operating	B-General_Concept
system	I-General_Concept
process	B-Operating_System
.	O
</s>
<s>
A	O
process	B-Operating_System
may	O
contain	O
many	O
application	B-Architecture
domains	I-Architecture
.	O
</s>
<s>
Application	B-Architecture
domains	I-Architecture
have	O
isolation	O
properties	O
similar	O
to	O
that	O
of	O
operating	B-General_Concept
system	I-General_Concept
processes	O
:	O
</s>
<s>
Multiple	O
threads	B-Operating_System
can	O
exist	O
within	O
a	O
single	O
application	B-Architecture
domain	I-Architecture
.	O
</s>
<s>
An	O
application	O
within	O
a	O
domain	O
can	O
be	O
stopped	O
without	O
affecting	O
the	O
state	O
of	O
another	O
domain	O
in	O
the	O
same	O
process	B-Operating_System
.	O
</s>
<s>
A	O
fault	O
or	O
exception	O
in	O
one	O
domain	O
does	O
not	O
affect	O
an	O
application	O
in	O
another	O
domain	O
or	O
crash	O
the	O
entire	O
process	B-Operating_System
that	O
hosts	O
the	O
domains	O
.	O
</s>
<s>
Configuration	O
information	O
is	O
part	O
of	O
a	O
domain	O
's	O
scope	B-Language
,	O
not	O
the	O
scope	B-Language
of	O
the	O
process	B-Operating_System
.	O
</s>
<s>
It	O
runs	O
a	O
single	O
process	B-Operating_System
that	O
contains	O
a	O
number	O
of	O
sub-processes	O
,	O
or	O
application	B-Architecture
domains	I-Architecture
.	O
</s>
<s>
The	O
advantage	O
of	O
application	B-Architecture
domains	I-Architecture
is	O
that	O
running	O
multiple	O
application	B-Architecture
domains	I-Architecture
may	O
require	O
fewer	O
resources	O
,	O
such	O
as	O
memory	O
,	O
than	O
running	O
multiple	O
operating	B-General_Concept
system	I-General_Concept
processes	O
.	O
</s>
<s>
Communication	O
between	O
domains	O
still	O
requires	O
marshalling	B-Application
,	O
so	O
the	O
overheads	O
can	O
be	O
closer	O
to	O
using	O
multiple	O
processes	O
than	O
to	O
communicating	O
within	O
a	O
single	O
domain	O
.	O
</s>
<s>
Direct	O
communication	O
cannot	O
be	O
achieved	O
across	O
application	B-Architecture
domains	I-Architecture
.	O
</s>
<s>
However	O
,	O
application	B-Architecture
domains	I-Architecture
can	O
still	O
talk	O
to	O
each	O
other	O
by	O
passing	O
objects	O
via	O
marshalling	B-Application
by	O
value	O
(	O
unbound	O
objects	O
)	O
,	O
marshalling	B-Application
by	O
reference	O
through	O
a	O
proxy	O
(	O
application-domain-bound	O
objects	O
)	O
.	O
</s>
<s>
There	O
is	O
a	O
third	O
type	O
of	O
object	O
called	O
a	O
context-bound	O
object	O
which	O
can	O
be	O
marshalled	O
by	O
reference	O
across	O
domains	O
and	O
also	O
within	O
the	O
context	O
of	O
its	O
own	O
application	B-Architecture
domain	I-Architecture
.	O
</s>
<s>
Because	O
of	O
the	O
verifiable	O
type-safety	B-Language
of	O
managed	O
code	O
,	O
a	O
CLI	O
can	O
provide	O
fault	O
isolation	O
between	O
domains	O
at	O
a	O
much	O
lower	O
cost	O
than	O
an	O
operating	B-General_Concept
system	I-General_Concept
process	B-Operating_System
can	O
.	O
</s>
<s>
The	O
static	O
type	O
verification	O
used	O
for	O
isolation	O
does	O
not	O
require	O
the	O
same	O
process	B-Operating_System
switches	O
or	O
hardware	O
ring	O
transitions	O
that	O
an	O
operating	B-General_Concept
system	I-General_Concept
process	B-Operating_System
requires	O
.	O
</s>
<s>
Application	B-Architecture
domains	I-Architecture
are	O
a	O
purely	O
managed	O
code	O
concept	O
.	O
</s>
<s>
Any	O
included	O
native/unmanaged	O
code	O
(	O
e.g.	O
,	O
C++	O
)	O
is	O
largely	O
unaware	O
of	O
them	O
.	O
</s>
