Week 79: What's the Diff

On Wikipedia, a "diff" page displays the differences between two versions of another page. Diffs can be found on history pageswatchlists, and other pages showing revision histories.

For the sake of clarity, here's an example diff where some new information was added. And from the same page, an example diff where some was removed. Here's what to look for:

  • At left is the older version of the page, and the newer one is at right.
  • There is some color-coding:
    • Unchanged paragraphs are contained in a light gray box.
    • Changed paragraphs are highlighted with a yellow border (older version) or a blue border (newer version).
    • The changed text itself is also highlighted and bolded.
  • Paragraphs removed are still visible at left, but disappear in the column at right.

There's more to say about how diffs work, and we'll pick that up next week.