Next: Setting up Subversion
Subversion is a way of keeping track of changes that have been made to files. It makes it easy to go back to an earlier version of a file, and to allow multiple people to work on code simultaneously.
One of the nice features of subversion is in the way it allows multiple people to work on the same project, without interfering with each others work. If Martha and George are both working on the same code, they can look to see what changes the other person has made, and then decide what to do. Subversion makes it easy for them to see who has made what changes, what changes are likely to interfere with each other, and decide which changes to keep.
If Martha and George are working on the same project, and George is doing minor bug fixes, but Martha is working on a new feature, it makes sense for them to work separately for a while. This way, Martha can make major changes, and save frequently, but not interfere with the code that George is troubleshooting. But, we also want a way to fold Martha's new feature back into the main code. So, Martha starts a branch, which is an exact copy of the main code, and starts working on that. She can make changes and save, and when she is ready to fold parts or all of her code back into the main trunk, svn has the the tools to make that relatively simple. For example, you can look at files which you have both changed (one was changed in the trunk, the other in the branch), and see all the changes at once that each of you have made, even though you have technically been working on different files.
Next: Setting up Subversion