branch

A source code version control concept where code is "split" into many different versions which allows changes to be made without affecting the main branch of code.

Imagine, for a moment, that you are the project leader of a software development team. You have a product, "foo" version 1.0, that has just been released to a happy and receptive public. (yeah, right! :-) However, the increased exposure of your product to a larger user base has shown it has several bugs and customers have also submitted several enhancement requests. Senior management has told you to:

• Fix the bugs in version 1.0 and release a bug fix service pack.
• Add the features requested by your customers and release a new version of foo.

A good version control system will help you accomplish this by splitting the code into two branches:

1. Before branching. Here there is only one version of the software. When a developer wishes to work on the project, he/she only has one choice of what version of software to change.

   (released version of software)
   +-----+
   ! 1.0 !
   +-----+
   

2. After branching. Here the developer can check out the project from either the 1.1 branch or the 1.8 "main trunk." If they are working on bug fixes they will use the 1.1 branch as a basis for their work, if they are adding features they will use the 1.8 branch. Version 1.8 is the result of many code changes as features are added to the product (hence producing 1.2, 1.3 etc etc as changes are made)

   +-----+  some versions  +-----+
   ! 1.0 !-- omitted for --! 1.8 ! (pre version 2.0
   +-----+     clarity     +-----+    work)
      !
      !   +-----+
      +---! 1.1 ! (bug fixes)
          +-----+
   

3. Of course, it is desirable that version 2.0 of the product will incorporate the bug fixes from the version 1.1 work. This is accomplished by merging the 1.1 branch back into the main trunk. (merging is beyond the scope of this node, and is only simply illustrated here) The project leader or build manager will usually accomplish this task, consulting with the engineers who are responsible for the project. Here, the changes from version 1.1 have been merged back into the main trunk. The changes have combined with version 1.8 to form a new version, 1.9. This new version will incorporate both the changes from 1.1 and the feature requests that have been added to form 1.8

   +-----+    +-----+    +-----+
   ! 1.0 !----! 1.8 !----! 1.9 ! (new version)
   +-----+    +-----+  / +-----+
      !               /
      !   +-----+    / (merge)
      +---! 1.1 !---+
          +-----+
        (bug fixes)
   
   

Of course, this is greatly simplified, to fit well into a node.

ASCII art adapted from the CVS manual at http://www.cvshome.org/

Branch (?), n.; pl. Branches (). [OE. braunche, F. branche, fr. LL. branca claw of a bird or beast of prey; cf. Armor. brank branch, bough.]

1. Bot.

A shoot or secondary stem growing from the main stem, or from a principal limb or bough of a tree or other plant.

2.

Any division extending like a branch; any arm or part connected with the main body of thing; ramification; as, the branch of an antler; the branch of a chandelier; a branch of a river; a branch of a railway.

Most of the branches , or streams, were dried up. W. Irving.

3.

Any member or part of a body or system; a distinct article; a section or subdivision; a department.

Prescott.

It is a branch and parcel of mine oath. Shak.

4. Geom.

One of the portions of a curve that extends outwards to an indefinitely great distance; as, the branches of an hyperbola.

5.

A line of family descent, in distinction from some other line or lines from the same stock; any descendant in such a line; as, the English branch of a family.

His father, a younger branch of the ancient stock. Carew.

6. Naut.

A warrant or commission given to a pilot, authorizing him to pilot vessels in certain waters.

Branches of a bridle, two pieces of bent iron, which bear the bit, the cross chains, and the curb. -- Branch herring. See Alewife. -- Root and branch , totally, wholly.

Syn. -- Bough; limb; shoot; offshoot; twig; sprig.

© Webster 1913.

Branch (?), a.

Diverging from, or tributary to, a main stock, line, way, theme, etc.; as, a branch vein; a branch road or line; a branch topic; a branch store.

© Webster 1913.

Branch, v. i. [imp. & p. p. Branched (#); p. pr. & vb. n. Branching.]

1.

To shoot or spread in branches; to separate into branches; to ramify.

2.

To divide into separate parts or subdivision.

To branch off, to form a branch or a separate part; to diverge. -- To branch out, to speak diffusively; to extend one's discourse to other topics than the main one; also, to enlarge the scope of one's business, etc.

To branch out into a long disputation. Spectator.

© Webster 1913.

Branch, v. t.

1.

To divide as into branches; to make subordinate division in.

2.

To adorn with needlework representing branches, flowers, or twigs.

The train whereof loose far behind her strayed, Branched with gold and pearl, most richly wrought. Spenser.

© Webster 1913.