<s>
The	O
space	B-Device
bar	I-Device
,	O
spacebar	B-Device
,	O
blank	O
,	O
or	O
space	B-Device
key	I-Device
is	O
a	O
key	O
on	O
a	O
typewriter	O
or	O
alphanumeric	B-Device
keyboard	I-Device
in	O
the	O
form	O
of	O
a	O
horizontal	O
bar	O
in	O
the	O
lowermost	O
row	O
,	O
significantly	O
wider	O
than	O
all	O
other	O
keys	O
.	O
</s>
<s>
Its	O
main	O
purpose	O
is	O
to	O
conveniently	O
enter	O
a	O
space	O
,	O
e.g.	O
,	O
between	O
words	O
during	O
typing	B-Application
.	O
</s>
<s>
Originally	O
,	O
(	O
on	O
early	O
writers	O
dating	O
back	O
to	O
the	O
late	O
19th	O
century	O
)	O
the	O
"	O
bar	O
"	O
was	O
literally	O
a	O
metal	O
bar	O
running	O
across	O
the	O
full	O
width	O
of	O
the	O
keyboard	B-Device
(	O
or	O
even	O
wider	O
,	O
and	O
even	O
surrounding	O
it	O
)	O
that	O
triggered	O
the	O
carriage	O
advance	O
without	O
also	O
firing	O
any	O
of	O
the	O
typebars	O
towards	O
the	O
platen	O
.	O
</s>
<s>
Later	O
examples	O
gradually	O
shrank	O
and	O
developed	O
into	O
their	O
current	O
more	O
ergonomic	O
form	O
as	O
a	O
wide	O
,	O
centrally	O
located	O
but	O
otherwise	O
apparently	O
normal	O
"	O
key	O
"	O
,	O
as	O
typewriter	O
(	O
and	O
computer	O
)	O
keyboards	B-Device
began	O
to	O
incorporate	O
additional	O
function	O
keys	O
and	O
were	O
more	O
deliberately	O
"	O
styled	O
"	O
.	O
</s>
<s>
Although	O
it	O
varies	O
by	O
keyboard	B-Device
type	O
,	O
the	O
space	B-Device
bar	I-Device
usually	O
lies	O
between	O
the	O
Alt	O
keys	O
(	O
or	O
Command	O
keys	O
on	O
Macintosh	O
keyboards	B-Device
)	O
and	O
below	O
the	O
letter	O
keys	O
:	O
C	O
,	O
V	O
,	O
B	O
,	O
N	O
and	O
M	O
on	O
a	O
standard	O
QWERTY	O
keyboard	B-Device
.	O
</s>
<s>
In	O
some	O
keyboards	B-Device
,	O
both	O
physical	O
and	O
specially	O
virtual	O
ones	O
,	O
the	O
symbol	O
is	O
used	O
to	O
label	O
the	O
space	B-Device
bar	I-Device
.	O
</s>
<s>
Some	O
early	O
typewriter	O
and	O
particularly	O
computer	O
keyboards	B-Device
used	O
a	O
different	O
method	O
of	O
inserting	O
spaces	O
,	O
typically	O
a	O
smaller	O
,	O
less	O
distinct	O
"	O
space	O
"	O
key	O
which	O
was	O
also	O
often	O
set	O
in	O
a	O
less	O
central	O
position	O
,	O
e.g.	O
</s>
<s>
the	O
Hansen	O
Writing	O
Ball	O
,	O
Hammond	O
typewriters	O
or	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
and	O
Jupiter	B-Language
Ace	I-Language
ranges	O
.	O
</s>
<s>
The	O
earliest	O
known	O
example	O
,	O
Sholes	O
and	O
Glidden	O
typewriter	O
used	O
a	O
lever	O
to	O
provide	O
space	O
between	O
words	O
,	O
placing	O
the	O
invention	O
of	O
the	O
inset	O
spacebar	B-Device
after	O
1843	O
.	O
</s>
<s>
However	O
these	O
methods	O
were	O
also	O
usually	O
just	O
one	O
part	O
of	O
similarly	O
idiosyncratic	O
full	O
keyboard	B-Device
layouts	O
,	O
designed	O
more	O
to	O
cope	O
with	O
particular	O
technical	O
requirements	O
or	O
limitations	O
than	O
with	O
any	O
sense	O
of	O
user	O
friendliness	O
and	O
as	O
such	O
met	O
with	O
limited	O
success	O
,	O
sometimes	O
being	O
dropped	O
even	O
on	O
later	O
models	O
in	O
the	O
same	O
line	O
(	O
e.g.	O
</s>
<s>
Sinclair	B-Operating_System
Spectrum	I-Operating_System
128k	O
and	O
"	O
Plus	O
"	O
lines	O
,	O
which	O
adopted	O
more	O
"	O
normally	O
styled	O
"	O
keyboards	B-Device
with	O
plastic	O
keytops	O
and	O
a	O
wide	O
,	O
central	O
spacebar	B-Device
in	O
place	O
of	O
the	O
earlier	O
rubber	O
"	O
chiclet	O
"	O
keys	O
and	O
small	O
,	O
offset	O
space	B-Device
key	I-Device
)	O
.	O
</s>
<s>
Depending	O
on	O
the	O
operating	B-General_Concept
system	I-General_Concept
,	O
the	O
space	B-Device
bar	I-Device
used	O
with	O
a	O
modifier	B-Device
key	I-Device
such	O
as	O
the	O
control	B-Device
key	I-Device
may	O
have	O
functions	O
such	O
as	O
resizing	O
or	O
closing	O
the	O
current	O
window	O
,	O
half-spacing	O
,	O
or	O
even	O
backspacing	O
.	O
</s>
<s>
On	O
web	O
browsers	O
,	O
the	O
space	B-Device
bar	I-Device
usually	O
allows	O
the	O
user	O
to	O
page	O
down	O
or	O
to	O
page	O
up	O
when	O
the	O
space	B-Device
bar	I-Device
is	O
used	O
with	O
the	O
Shift	O
key	O
.	O
</s>
<s>
In	O
many	O
programs	O
for	O
playback	O
of	O
linear	O
media	O
(	O
such	O
as	O
videos	O
or	O
music	O
)	O
,	O
the	O
space	B-Device
bar	I-Device
is	O
used	O
for	O
pausing	O
and	O
resuming	O
playback	O
,	O
or	O
for	O
manually	O
advancing	O
through	O
text	O
.	O
</s>
<s>
In	O
video	O
games	O
where	O
the	O
playable	O
character	O
can	O
move	O
and	O
jump	O
,	O
the	O
default	O
key	O
to	O
jump	O
is	O
usually	O
the	O
space	B-Device
bar	I-Device
.	O
</s>
<s>
This	O
is	O
usually	O
used	O
along	O
with	O
the	O
WASD	O
keys	O
for	O
up	B-Device
,	I-Device
down	I-Device
,	I-Device
left	I-Device
and	I-Device
right	I-Device
movement	O
.	O
</s>
