Please correct me if I am wrong:

The number of parents of a commit can be:

• 0 - only for the initial commit in the REPO
• 1 - for a simple commit on some branch
• 2 - for a merge commit

The number of parents cannot be more than 2.

The number of children can be any non-negative number.

• Zero for commit on the tip of one or more branches
• One for simple commit on a branch
• Any value greater than one if several branches were created out of a commit and these branches have commits.

CodePudding user response：

The number of parents can be any non-negative number, see the octopus strat, and a 0-parent commit can be added at any time, though there's legitimate debate over that usage such debates tend to be settled in favor of usefulness.