Software teams that do not use any form of version control often run into problems like not knowing which changes that have been made are available to users or the creation of incompatible changes between two unrelated pieces of work that must then be painstakingly untangled and reworked. Great version control systems facilitate a smooth and continuous flow of changes to the code rather than the frustrating and clumsy mechanism of file locking - giving the green light to one developer at the expense of blocking the progress of others. Ideally it also works on any platform, rather than dictate what operating system or tool chain developers must use. Good version control software supports a developer's preferred workflow without imposing one particular way of working. So testing and development proceed together until a new version is ready.

Further, in all software development, any change can introduce new bugs on its own and new software can't be trusted until it's tested. This problem should be discovered and solved in an orderly manner without blocking the work of the rest of the team. Changes made in one part of the software can be incompatible with those made by another developer working at the same time.

Version control helps teams solve these kinds of problems, tracking every individual change by each contributor and helping prevent concurrent work from conflicting. One developer on the team may be working on a new feature while another developer fixes an unrelated bug by changing code, each developer may make their changes in several parts of the file tree. The code for a project, app or software component is typically organized in a folder structure or 'file tree'. Software developers working in teams are continually writing new source code and changing existing source code.

Version control protects source code from both catastrophe and the casual degradation of human error and unintended consequences. For most software teams, the source code is a repository of the invaluable knowledge and understanding about the problem domain that the developers have collected and refined through careful effort. For almost all software projects, the source code is like the crown jewels - a precious asset whose value must be protected.

Basic java projects with source code