From a storage perspective, describing commits as snapshots seems like a bad mental model. Suppose I have a directory that is 100MB in size. If I take a snapshot of it, my snapshot would be 100MB in size. If I take a 2nd snapshot of it tomorrow, my 2nd snapshot would also be 100MB in size. My total storage needs would now be 300MB.<p>Whereas if I had used git, and created 2 additional commits, each making a change to a small text file, my total storage size would be barely larger than 100MB. Describing the commits as a diff, as opposed to a snapshot, leads to a better intuitive understanding of why this would be the case.<p>Not to mention other features the article discussed, such as cherry-picking. What does it even mean to "cherry-pick a snapshot"? In comparison, cherry-picking a diff and applying it to your current state, is far more intuitive.<p>And let's not forget commit messages. If a commit is a snapshot, I would expect the commit-message to be descriptive of the entire snapshot. Whereas if a commit is a diff, I would expect the commit message to be descriptive of the diff. Which is exactly how most people use commit messages.<p>Obviously both "diffs" and "snapshots" are leaky abstractions. If you insist on using the "snapshot" abstraction, you will need to resolve all of the above points of confusion by adding more complexity to your abstraction. And if you prefer to use the "diff" abstraction, you will eventually need to explain that a commit is actually a combination of diffs, along with some other metadata like a pointer to a parent commit. As a teaching tool, you can make either abstraction work. But I find it far more intuitive and useful to think of commits as "diffs + some metadata".