Git Rebase is a version control operation in Git that allows users to integrate changes from one branch into another by reapplying commits on top of the target branch. Unlike merging, which creates a new commit to combine changes, rebasing rewrites the commit history, creating a linear sequence of commits.

Key Features:
1. Commit Reordering: Changes from the source branch are applied sequentially on top of the target branch.
2. Interactive Rebase: Enables users to edit, squash, or reorder commits during the rebasing process.
3. Conflict Resolution: Conflicts during rebase must be resolved manually before continuing.

Use Cases:
- Clean Commit History: Rebasing creates a streamlined and linear history, making it easier to understand changes.
- Feature Branch Integration: Reapply feature branch changes onto an updated main branch to ensure compatibility.

Risks and Best Practices:
- History Rewrite: Rebasing changes commit IDs, which can create issues in shared branches. It is recommended to avoid rebasing publicly shared branches.
- Backups: Always create backups or branches before performing a rebase to recover from potential errors.

By mastering Git Rebase, developers can maintain clean, understandable project histories while efficiently integrating changes.