What it is: Git is a free, open-source Distributed Version Control System (DVCS). Every clone is a full repository with complete history, so work continues even offline and collaboration is fast.

1. Complete history - Every change to every file is recorded with author, timestamp, and a message—enabling rollbacks, bisects, and fixes to older releases.
2. Branching & merging- Safe parallel work on features, fixes, and releases. Merge (or rebase) brings streams back together while surfacing conflicts early.
3. Traceability - Link commits to issues (e.g., Jira), annotate intent via messages, and understand why code exists—critical for legacy systems and better estimates.

Git vs. centralized VCS

• Distributed Version Control Systems (DVCSs) (Git): local commits, fast history queries, easy branching, offline work, cheap forks.
• Centralized Version Control Systems (CVCSs) (e.g., SVN) : single server history, simpler mental model but slower branching/merging and needs network access.

Common branching models

• Trunk-Based Development: small, frequent merges to main; use short-lived feature branches + feature flags.
• Git Flow: long-lived develop + release/hotfix branches (heavier, suits regulated or scheduled releases).
• GitHub Flow: branch off main → PR → review → merge → deploy (great for continuous deliver

Terminology

• Branch — a movable pointer to a commit; independent line of development.
• Centralized workflow — everyone commits to a single mainline (e.g., Subversion-style); with Git, this means pushing straight to main with minimal branching.
• Feature branch workflow — create a branch per feature/fix; open a PR/MR; merge when reviewed.
• Forking — copy a repository into your own namespace (common on GitHub); propose changes via pull requests back upstream.
• Gitflow workflow — a branching model with long-lived main and develop, plus feature/, release/, and hotfix/ branches.
• HEAD — your current position in history (usually points to the latest commit on the checked-out branch).