Objects are your files. Underlying git is a content-addressable filesystem.
The objects are referenced by trees. A tree is just a directory.
The trees are then referenced by commits and/or tags into a DAG with named pointers into various parts of it (which are your branch and tag references):
https://git-scm.com/book/en/v2/Git-Internals-Git-Objects
Because it would be terribly in-efficient to have a bunch of loose objects, git periodically groups them together into packs. To save space, the objects are compressed against one another (delta compression) within the packs.
https://git-scm.com/docs/git-pack-objects
https://github.com/git/git/blob/master/Documentation/technic...
When pushing or pulling, the git transfer protocol basically enumerates what objects each side has so that it only needs to transfer the difference. On top of that, it delta compresses the objects on each side that aren't already grouped into packs against each other to save space.
https://github.com/git/git/blob/master/Documentation/technic...
Because git is an open-source project written by nerds, it shows you all of this information. Feel free to ignore it!
But if you really want to know, it's all documented both in the git book and git documentation directory, both linked above.
(Caveat: I'm working from memory and surely got some detail at least slightly wrong.)
The objects are referenced by trees. A tree is just a directory.
The trees are then referenced by commits and/or tags into a DAG with named pointers into various parts of it (which are your branch and tag references):
https://git-scm.com/book/en/v2/Git-Internals-Git-Objects
Because it would be terribly in-efficient to have a bunch of loose objects, git periodically groups them together into packs. To save space, the objects are compressed against one another (delta compression) within the packs.
https://git-scm.com/docs/git-pack-objects
https://github.com/git/git/blob/master/Documentation/technic...
When pushing or pulling, the git transfer protocol basically enumerates what objects each side has so that it only needs to transfer the difference. On top of that, it delta compresses the objects on each side that aren't already grouped into packs against each other to save space.
https://github.com/git/git/blob/master/Documentation/technic...
Because git is an open-source project written by nerds, it shows you all of this information. Feel free to ignore it!
But if you really want to know, it's all documented both in the git book and git documentation directory, both linked above.
(Caveat: I'm working from memory and surely got some detail at least slightly wrong.)