<s>
In	O
computing	O
,	O
resident	B-General_Concept
set	I-General_Concept
size	I-General_Concept
(	O
RSS	O
)	O
is	O
the	O
portion	O
of	O
memory	O
(	O
measured	O
in	O
kilobytes	O
)	O
occupied	O
by	O
a	O
process	B-Operating_System
that	O
is	O
held	O
in	O
main	O
memory	O
(	O
RAM	B-Architecture
)	O
.	O
</s>
<s>
The	O
rest	O
of	O
the	O
occupied	O
memory	O
exists	O
in	O
the	O
swap	O
space	O
or	O
file	B-Application
system	I-Application
,	O
either	O
because	O
some	O
parts	O
of	O
the	O
occupied	O
memory	O
were	O
paged	B-Architecture
out	I-Architecture
,	O
or	O
because	O
some	O
parts	O
of	O
the	O
executable	O
were	O
never	O
loaded	O
.	O
</s>
