WTF is a detached HEAD in git?

Git Tutorial 7: What is HEAD? How Git Works: Explained in 4 Minutes Using Git: What is a \"Detached HEAD\"? 5 Git: HEAD - что такое указатель? Git branches and Git HEAD: 55 What is HEAD in Git Git Explained in 100 Seconds Git Detached HEAD Explained: Causes, Dangers & How to Fix It What is HEAD in Git What Exactly Is HEAD In Git? Demystifying The Mystery! Git HEAD Explained: Understanding the Current Branch Pointer Learn Git Essentials 9: Head & Detached Head What is HEAD in Git? Explained for Beginners Git Tutorial Deutsch #5 - Git Checkout und HEAD Git Internals: Demystifying References, Branches & HEAD Git branches and Git HEAD: 59 Why do we need branches 5.1 Git: HEAD - что такое смещенный указатель? Basics of Git - Part 5 - How the HEAD Works