Git is a distributed version control system that tracks changes in source code during software development. It's designed for coordinating work among programmers, but it can be used to track changes in any set of files.

Key concepts include:
- Repository
- Commit
- Branch
- Merge
- Pull Request
- Clone
- Push/Pull

A Git branching strategy is a convention or set of rules that specify how and when branches should be created and merged. Common strategies include:

1. **Git Flow:**
   - Main branches: master, develop
   - Supporting branches: feature, release, hotfix

2. **Trunk-Based Development:**
   - Single main branch (trunk)
   - Short-lived feature branches
   - Frequent integration

Example of creating a feature branch:
```bash
# Create and switch to a new feature branch
git checkout -b feature/new-feature

# Make changes and commit
git add .
git commit -m "Add new feature"

# Push to remote
git push origin feature/new-feature
```