<s>
Branching	B-General_Concept
,	O
in	O
version	B-Architecture
control	I-Architecture
and	O
software	O
configuration	O
management	O
,	O
is	O
the	O
duplication	O
of	O
an	O
object	O
under	O
version	B-Architecture
control	I-Architecture
(	O
such	O
as	O
a	O
source	O
code	O
file	O
or	O
a	O
directory	B-Application
tree	I-Application
)	O
.	O
</s>
<s>
The	O
users	O
of	O
the	O
version	B-Architecture
control	I-Architecture
system	I-Architecture
can	O
branch	O
any	O
branch	O
.	O
</s>
<s>
Child	O
branches	O
are	O
branches	O
that	O
have	O
a	O
parent	O
;	O
a	O
branch	O
without	O
a	O
parent	O
is	O
referred	O
to	O
as	O
the	O
trunk	O
or	O
the	O
mainline	B-General_Concept
.	O
</s>
<s>
The	O
trunk	O
is	O
also	O
sometimes	O
loosely	O
referred	O
to	O
as	O
HEAD	O
,	O
but	O
properly	O
head	O
refers	O
not	O
to	O
a	O
branch	O
,	O
but	O
to	O
the	O
most	O
recent	O
commit	B-Language
on	O
a	O
given	O
branch	O
,	O
and	O
both	O
the	O
trunk	O
and	O
each	O
named	O
branch	O
has	O
its	O
own	O
head	O
.	O
</s>
<s>
Another	O
approach	O
is	O
to	O
split	O
a	O
branch	O
off	O
the	O
trunk	O
,	O
implement	O
changes	O
in	O
that	O
branch	O
and	O
merge	B-General_Concept
the	O
changes	O
back	O
into	O
the	O
trunk	O
when	O
the	O
branch	O
has	O
proven	O
to	O
be	O
stable	O
and	O
working	O
.	O
</s>
<s>
Depending	O
on	O
development	O
mode	O
and	O
commit	B-Language
policy	O
the	O
trunk	O
may	O
contain	O
the	O
most	O
stable	O
or	O
the	O
least	O
stable	O
or	O
something-in-between	O
version	O
.	O
</s>
<s>
Other	O
terms	O
for	O
trunk	O
include	O
baseline	O
,	O
mainline	B-General_Concept
,	O
and	O
master	O
,	O
though	O
in	O
some	O
cases	O
these	O
are	O
used	O
with	O
similar	O
but	O
distinct	O
senses	O
–	O
see	O
.	O
</s>
<s>
Often	O
main	O
developer	O
work	O
takes	O
place	O
in	O
the	O
trunk	O
and	O
stable	O
versions	O
are	O
branched	O
,	O
and	O
occasional	O
bug-fixes	O
are	O
merged	B-General_Concept
from	O
branches	O
to	O
the	O
trunk	O
.	O
</s>
<s>
In	O
some	O
distributed	B-Protocol
revision	I-Protocol
control	I-Protocol
systems	I-Protocol
,	O
such	O
as	O
Darcs	B-Protocol
,	O
there	O
is	O
no	O
distinction	O
made	O
between	O
repositories	B-General_Concept
and	O
branches	O
;	O
in	O
these	O
systems	O
,	O
fetching	O
a	O
copy	O
of	O
a	O
repository	B-General_Concept
is	O
equivalent	O
to	O
branching	B-General_Concept
.	O
</s>
<s>
Branching	B-General_Concept
also	O
generally	O
implies	O
the	O
ability	O
to	O
later	O
merge	B-General_Concept
or	O
integrate	O
changes	O
back	O
onto	O
the	O
parent	O
branch	O
.	O
</s>
<s>
Often	O
the	O
changes	O
are	O
merged	B-General_Concept
back	O
to	O
the	O
trunk	O
,	O
even	O
if	O
this	O
is	O
not	O
the	O
parent	O
branch	O
.	O
</s>
<s>
A	O
branch	O
not	O
intended	O
to	O
be	O
merged	B-General_Concept
(	O
e.g.	O
</s>
<s>
because	O
it	O
has	O
been	O
relicensed	O
under	O
an	O
incompatible	O
license	O
by	O
a	O
third	O
party	O
,	O
or	O
it	O
attempts	O
to	O
serve	O
a	O
different	O
purpose	O
)	O
is	O
usually	O
called	O
a	O
fork	B-Application
.	O
</s>
<s>
Branches	O
allow	O
contributors	O
to	O
isolate	O
changes	O
without	O
destabilizing	O
the	O
codebase	O
,	O
for	O
example	O
,	O
fixes	O
for	O
bugs	O
,	O
new	O
features	B-Architecture
,	O
and	O
versions	O
integration	O
.	O
</s>
<s>
These	O
changes	O
may	O
be	O
later	O
merged	B-General_Concept
(	O
resynchronized	O
)	O
after	O
testing	O
.	O
</s>
<s>
In	O
the	O
open	B-License
source	I-License
community	O
,	O
the	O
notion	O
of	O
release	O
is	O
typically	O
metaphorical	O
,	O
since	O
anyone	O
can	O
usually	O
check	O
out	O
any	O
desired	O
version	O
,	O
whether	O
it	O
be	O
in	O
the	O
development	O
branch	O
or	O
not	O
.	O
</s>
<s>
Some	O
revision	B-Architecture
control	I-Architecture
systems	I-Architecture
have	O
specific	O
jargon	O
for	O
the	O
main	O
development	O
branch	O
.	O
</s>
<s>
For	O
example	O
,	O
in	O
CVS	B-Application
,	O
it	O
is	O
called	O
the	O
"	O
MAIN	O
"	O
branch	O
.	O
</s>
<s>
Git	B-Application
uses	O
"	O
master	O
"	O
by	O
default	O
,	O
although	O
GitHub	B-Application
and	O
GitLab	B-Application
switched	O
to	O
"	O
main	O
"	O
after	O
the	O
murder	O
of	O
George	O
Floyd	O
.	O
</s>
<s>
In	O
CVSNT	B-Protocol
,	O
a	O
shadow	O
or	O
magic	O
branch	O
"	O
shadows	O
"	O
changes	O
made	O
in	O
the	O
upstream	O
branch	O
,	O
to	O
make	O
it	O
easier	O
to	O
maintain	O
small	O
changes	O
(	O
cvc	O
is	O
an	O
open-source	B-License
package	O
building	O
system	O
incorporating	O
a	O
revision-control	O
system	O
for	O
packages	O
produced	O
by	O
rPath	B-Operating_System
.	O
)	O
</s>
<s>
In	O
distributed	B-Protocol
revision	I-Protocol
control	I-Protocol
,	O
the	O
entire	O
repository	B-General_Concept
,	O
with	O
branches	O
,	O
may	O
be	O
copied	O
and	O
worked	O
on	O
further	O
.	O
</s>
<s>
Monotone	B-Application
(	O
mtn	O
)	O
,	O
Mercurial	B-Protocol
(	O
hg	B-Protocol
)	O
and	O
git	B-Application
call	O
it	O
"	O
clone	O
"	O
;	O
Bazaar	B-Protocol
calls	O
it	O
"	O
branch	O
"	O
.	O
</s>
