Atomic Commits are a concept in version control systems that ensure that all changes included in a commit are applied completely and consistently. This means that a commit is either fully executed or not executed at all—there is no intermediate state. This property guarantees the integrity of the repository and prevents inconsistencies.

Key features and benefits of Atomic Commits include:

1. Consistency: A commit is only saved if all changes included in it are successful. This ensures that the repository remains in a consistent state after each commit.

2. Error Prevention: If an error occurs (e.g., a network problem or a conflict), the commit is aborted, and the repository remains unchanged. This prevents partially saved changes that could lead to issues.

3. Unified Changes: All files modified in a commit are treated together. This is particularly important when changes to multiple files are logically related and need to be considered as a unit.

4. Traceability: Atomic Commits facilitate traceability and debugging since each change can be traced back as a coherent unit. If an issue arises, it can be easily traced back to a specific commit.

5. Simple Rollbacks: Since a commit represents a complete unit of change, unwanted changes can be easily rolled back by reverting to a previous state of the repository.

In Subversion (SVN) and other version control systems like Git, this concept is implemented to ensure the quality and reliability of the codebase. Atomic Commits are particularly useful in collaborative development environments where multiple developers are working simultaneously on different parts of the project.

Subversion, often abbreviated as SVN, is a widely-used version control system originally developed by CollabNet. It is designed to manage and track changes to files and directories over time. Subversion enables developers to efficiently manage, document, and synchronize changes to a project, especially when multiple people are working on the same project.

Key features of Subversion include:

1. Centralized Repository: Subversion uses a centralized repository where all files and their changes are stored. Developers check their changes into this central repository and retrieve the latest versions of files from it.

2. Versioning of Directories and Files: Subversion tracks changes not only to individual files but also to entire directories, making it easier to rename, move, or delete files and directories.

3. Branching and Merging: Subversion supports creating branches and merging changes. This is particularly useful for parallel development of features or managing release versions.

4. Atomic Commits: In Subversion, a commit is performed completely or not at all. This means all changes in a commit are treated as a single unit, ensuring data integrity.

5. Collaborative Development: Subversion facilitates team collaboration by detecting conflicts when the same files are edited simultaneously and providing mechanisms for conflict resolution.

6. Support for Binary Files: In addition to text files, Subversion can version binary files, making it versatile for various types of projects.

7. Integration with Development Environments: Numerous plugins and tools integrate Subversion with development environments like Eclipse, Visual Studio, and others, simplifying the workflow for developers.

Subversion is used in many projects and organizations to make software development and management more efficient and traceable. Despite the increasing popularity of distributed version control systems like Git, Subversion remains a preferred choice in many settings due to its stability and proven functionality.