What is a dangling commit and a blob in a Git repository and where do they come from?

What is a dangling commit and a blob in a Git repository and where do they come from?

git git-commit git-fsck git-dangling

git

Listing and deleting Git commits that are under no branch (dangling?)

git branch git-dangling

git

git: dangling blobs

git git-dangling

git

How to remove a dangling commit from GitHub?

git github git-dangling

git