Version control

Revision controlled project visualization-2010-24-02

Version control is a system that records changes to a file or set of files over time so that you can recall specific versions later. It is commonly used in software development to manage source code.

Types of Version Control Systems

There are several types of version control systems, each with its own features and use cases:

Local Version Control Systems

Local version control systems keep track of files within the local file system. One of the simplest forms of a local VCS is a database that keeps all changes to files under revision control.

Centralized Version Control Systems (CVCS)

Centralized version control systems, such as Subversion (SVN) and CVS, use a single server to store all the versioned files, and a number of clients that check out files from that central place.

Distributed Version Control Systems (DVCS)

Distributed version control systems, such as Git and Mercurial, allow clients to create mirrored repositories. Each clone is a full backup of all the data. This setup allows for more robust workflows and better collaboration.

Key Concepts

Repository

A repository (or "repo") is a data structure that stores metadata for a set of files or directory structure. Depending on the version control system, a repository can be stored locally or on a remote server.

Commit

A commit is a record of what changes were made to the repository. Each commit has a unique identifier, often a hash.

Branch

A branch is a parallel version of a repository. It allows you to work on different versions of a project simultaneously.

Merge

Merging is the process of combining changes from different branches. This is a common operation in version control systems to integrate changes from different lines of development.

Conflict

A conflict occurs when changes from different branches cannot be automatically merged. Conflicts must be resolved manually by the user.

Popular Version Control Systems

• Git
• Subversion
• Mercurial
• CVS
• Perforce

Benefits of Version Control

• **Collaboration**: Multiple people can work on the same project simultaneously.
• **Backup**: Every change is saved, so you can revert to previous versions if needed.
• **History**: Keeps a history of changes, which is useful for tracking progress and debugging.
• **Branching and Merging**: Facilitates parallel development and feature integration.

Related Pages

• Software development
• Git
• Subversion
• Mercurial (software)
• Concurrent Versions System
• Perforce
• Hash function
• Branch (software development)
• Merge (version control)

See Also

• Software configuration management
• Revision control
• Source code management