In brief
git bundle packages Git objects and references for transfer in a file. It can contain complete or incremental history depending on the selected range.
Useful to know
git bundle packages Git objects and references for transfer in a file. It can contain complete or incremental history depending on the selected range. [1]
Check prerequisites with bundle verify when receiving one. An incremental bundle may require commits already present. It is not an ordinary ZIP of the working directory and does not automatically include an external database, private settings or every local file.
Sources
For further detail and to check the information: