<s>
Horizontal	B-General_Concept
scan	I-General_Concept
rate	I-General_Concept
,	O
or	O
horizontal	O
frequency	O
,	O
usually	O
expressed	O
in	O
kilohertz	O
,	O
is	O
the	O
number	O
of	O
times	O
per	O
second	O
that	O
a	O
raster-scan	O
video	O
system	O
transmits	O
or	O
displays	O
a	O
complete	O
horizontal	O
line	O
,	O
as	O
opposed	O
to	O
vertical	O
scan	O
rate	O
,	O
the	O
number	O
of	O
times	O
per	O
second	O
that	O
an	O
entire	O
screenful	O
of	O
image	O
data	O
is	O
transmitted	O
or	O
displayed	O
.	O
</s>
<s>
Within	O
a	O
cathode-ray	B-Device
tube	I-Device
(	O
CRT	O
)	O
,	O
the	O
horizontal	B-General_Concept
scan	I-General_Concept
rate	I-General_Concept
is	O
how	O
many	O
times	O
in	O
a	O
second	O
that	O
the	O
electron	O
beam	O
moves	O
from	O
the	O
left	O
side	O
of	O
the	O
display	O
to	O
the	O
right	O
and	O
back	O
.	O
</s>
<s>
The	O
horizontal	B-General_Concept
scan	I-General_Concept
frequencies	I-General_Concept
of	O
a	O
CRT	O
include	O
some	O
intervals	O
that	O
occur	O
during	O
the	O
vertical	O
blanking	O
interval	O
,	O
so	O
the	O
horizontal	B-General_Concept
scan	I-General_Concept
rate	I-General_Concept
does	O
not	O
directly	O
correlate	O
to	O
visible	O
display	O
lines	O
unless	O
the	O
quantity	O
of	O
unseen	O
lines	O
are	O
also	O
known	O
.	O
</s>
<s>
The	O
horizontal	B-General_Concept
scan	I-General_Concept
rate	I-General_Concept
is	O
one	O
of	O
the	O
primary	O
figures	O
determining	O
the	O
resolution	B-Algorithm
capability	O
of	O
a	O
CRT	O
,	O
since	O
it	O
is	O
determined	O
by	O
how	O
quickly	O
the	O
electromagnetic	O
deflection	O
system	O
can	O
reverse	O
the	O
current	O
flowing	O
in	O
the	O
deflection	O
coil	O
in	O
order	O
to	O
move	O
the	O
electron	O
beam	O
from	O
one	O
side	O
of	O
the	O
display	O
to	O
the	O
other	O
.	O
</s>
<s>
While	O
other	O
display	O
technologies	O
such	O
as	O
liquid-crystal	B-Device
displays	I-Device
do	O
not	O
have	O
the	O
specific	O
electrical	O
characteristics	O
that	O
constrain	O
horizontal	B-General_Concept
scan	I-General_Concept
rates	I-General_Concept
on	O
CRTs	O
,	O
there	O
is	O
still	O
a	O
horizontal	B-General_Concept
scan	I-General_Concept
rate	I-General_Concept
characteristic	O
in	O
the	O
signals	O
that	O
drive	O
these	O
displays	O
.	O
</s>
