A properly formed Git commit subject line should always be able to complete the following sentence:

• If applied, this commit

Format:

[type](optional scope): [subject]

[optional body]

[optional footer]

Type

Must be one of the following:

• build - Build related changes
• chore - Build process or auxiliary tool changes
• docs - Documentation only changes
• feat - A new feature
• fix - A bug fix
• perf - A code change that improves performance
• refactor - A code change that neither fixes a bug or adds a feature
• revert - Reverting things
• style - Markup, white-space, formatting, missing semi-colons...
• test - Adding missing tests

Subject

The subject contains a succint description of the change:

• Use the imperative, present tense: "change" not "changed" nor "changes"
• No dot (.) at the end.

Scope

A scope may be provided to a commit’s type, to provide additional contextual information and is contained within parenthesis.

e.g., feat(parser): add ability to parse arrays.

Body

Just as in the subject, use the imperative, present tense: "change" not "changed" nor "changes". The body should include the motivation for the change and contrast this with previous behavior.

Rules

The 7 rules of a great commit message

1. Separate subject from body with a blank line
2. Limit the subject line to 50 characters
3. Summary in present tense. Not capitalized
4. Do not end the subject line with a period
5. Use the imperative mood in the subject line
6. Wrap the body at 72 characters
7. Use the body to explain what and why vs. how

For more details

https://www.conventionalcommits.org/en/v1.0.0/