What do “branch”, “tag” and “trunk” mean in Subversion repositories?

Question

I\'ve seen these words a lot around Subversion (and I guess general repository) discussions.
I have been using SVN for my projects for the last few year

Answer 1

I found this great tutorial regarding SVN when I was looking up the website of the author of the OpenCV 2 Computer Vision Application Programming Cookbook and I thought I should share.

He has a tutorial on how to use SVN and what the phrases 'trunk', 'tag' and 'branch' mean.

Cited directly from his tutorial:

The current version of your software project, on which your team is currently working is usually located under a directory called trunk. As the project evolves, the developer updates that version fix bugs, add new features) and submit his changes under that directory.

At any given point in time, you may want to freeze a version and capture a snapshot of the software as it is at this stage of the development. This generally corresponds to the official versions of your software, for example, the ones you will deliver to your clients. These snapshots are located under the tags directory of your project.

Finally, it is often useful to create, at some point, a new line of development for your software. This happens, for example, when you wish to test an alternative implementation in which you have to modify your software but you do not want to submit these changes to the main project until you decide if you adopt the new solution. The main team can then continue to work on the project while other developer work on the prototype. You would put these new lines of development of the project under a directory called branches.