<s>
In	O
tables	O
and	O
matrices	B-Architecture
,	O
a	O
column	B-Algorithm
group	I-Algorithm
or	O
row	B-Algorithm
group	I-Algorithm
usually	O
refers	O
to	O
a	O
subset	O
of	O
columns	O
or	O
rows	O
,	O
respectively	O
.	O
</s>
<s>
Short	O
names	O
or	O
notational	O
names	O
include	O
col	O
group	O
or	O
colgroup	O
,	O
and	O
row	B-Algorithm
group	I-Algorithm
or	O
rowgroup	B-General_Concept
.	O
</s>
<s>
In	O
web	O
development	O
,	O
colgroup	O
is	O
a	O
standard	O
HTML	O
attribute	O
and	O
an	O
HTML	O
event	O
attribute	O
,	O
for	O
example	O
used	O
for	O
color	O
formatting	O
of	O
entire	O
columns	O
in	O
HTML	B-General_Concept
tables	I-General_Concept
.	O
</s>
<s>
The	O
colgroup	O
tag	B-General_Concept
acts	O
as	O
a	O
"	O
parent	O
container	O
of	O
one	O
or	O
more	O
<col>	O
elements	O
"	O
.	O
</s>
<s>
Rowgroup	B-General_Concept
is	O
another	O
HTML	O
attribute	O
.	O
</s>
<s>
In	O
reporting	O
(	O
including	O
business	O
reporting	O
,	O
data	B-General_Concept
reporting	I-General_Concept
and	O
financial	O
reporting	O
)	O
,	O
colgroups	O
and	O
rowgroups	B-General_Concept
can	O
be	O
used	O
for	O
constructing	O
tables	O
and	O
matrices	B-Architecture
which	O
dynamically	O
adjusts	O
the	O
size	O
of	O
their	O
columns	O
and	O
rows	O
,	O
respectively	O
,	O
by	O
displaying	O
the	O
set	O
of	O
columns	O
in	O
the	O
colgroup	O
set	O
(	O
which	O
again	O
is	O
a	O
subset	O
of	O
the	O
underlying	O
data	O
)	O
.	O
</s>
<s>
In	O
reporting	O
,	O
colgroups	O
and	O
rowgroups	B-General_Concept
can	O
also	O
be	O
used	O
for	O
grouping	O
of	O
collapsible	O
categories	O
in	O
the	O
presentation	O
of	O
a	O
table	B-Application
(	O
with	O
or	O
without	O
aggregation	O
for	O
the	O
groups	O
)	O
.	O
</s>
<s>
One	O
example	O
of	O
a	O
use	O
case	O
may	O
be	O
if	O
a	O
table	B-Application
contains	O
a	O
lot	O
of	O
detailed	O
information	O
,	O
but	O
there	O
is	O
a	O
want	O
to	O
display	O
summarizing	O
information	O
of	O
groups	O
in	O
the	O
same	O
table	B-Application
.	O
</s>
