<s>
Read	B-General_Concept
–	I-General_Concept
write	I-General_Concept
memory	I-General_Concept
,	O
or	O
RWM	O
is	O
a	O
type	O
of	O
computer	B-General_Concept
memory	I-General_Concept
that	O
can	O
be	O
easily	O
written	O
to	O
as	O
well	O
as	O
read	O
from	O
using	O
electrical	O
signaling	O
normally	O
associated	O
with	O
running	O
a	O
software	O
,	O
and	O
without	O
any	O
other	O
physical	O
processes	O
.	O
</s>
<s>
The	O
related	O
storage	O
type	O
RAM	B-Architecture
means	O
something	O
different	O
;	O
it	O
refers	O
to	O
memory	O
that	O
can	O
access	O
any	O
memory	O
location	O
in	O
a	O
constant	O
amount	O
of	O
time	O
.	O
</s>
<s>
In	O
modern	O
computer	O
systems	O
using	O
memory	B-General_Concept
segmentation	I-General_Concept
,	O
each	O
segment	O
has	O
a	O
length	O
and	O
set	O
of	O
permissions	O
associated	O
with	O
it	O
.	O
</s>
<s>
Read	B-General_Concept
–	I-General_Concept
write	I-General_Concept
memory	I-General_Concept
is	O
composed	O
of	O
either	O
volatile	B-General_Concept
or	O
non-volatile	B-General_Concept
types	O
of	O
storage	O
.	O
</s>
<s>
Volatile	B-General_Concept
memory	I-General_Concept
is	O
usually	O
in	O
the	O
form	O
of	O
a	O
microchip	O
or	O
other	O
hardware	O
that	O
requires	O
an	O
external	O
power	O
source	O
to	O
enable	O
data	O
to	O
persist	O
.	O
</s>
<s>
Non-volatile	B-General_Concept
memory	I-General_Concept
is	O
considered	O
static	O
,	O
or	O
storage-type	O
memory	O
.	O
</s>
<s>
Typically	O
read-write	B-General_Concept
speeds	O
are	O
limited	O
to	O
its	O
bandwidth	O
or	O
have	O
mechanical	O
limitations	O
of	O
either	O
rotation	O
speeds	O
and	O
arm	O
movement	O
delays	O
for	O
storage	O
types	O
such	O
as	O
Cloud	O
Storage	O
,	O
Hard	B-Device
Disk	I-Device
Drive	I-Device
or	O
CD-RWs	O
,	O
DVD-RWs	O
,	O
SD	B-Device
cards	I-Device
,	O
Solid	B-Device
State	I-Device
Drive	I-Device
,	O
SRAM	B-Architecture
,	O
and	O
DRAM	O
,	O
or	O
other	O
integrated	O
circuitry	O
.	O
</s>
<s>
San	O
Francisco	O
in	O
1956	O
,	O
IBM	O
was	O
the	O
first	O
company	O
to	O
develop	O
and	O
sell	O
the	O
first	O
commercial	O
Hard	B-Device
Disk	I-Device
Drive	I-Device
(	O
HDD	O
)	O
.	O
</s>
