There are two types of general topics lists: Outlines and Indexes. Outlines are arranged hierarchically, while the topics in indexes are presented alphabetically.
The vast majority of lists on Wikipedia present the items of a class of things – those are item lists. The rest are general topics lists which are different than item lists because they present the subtopics of a given subject – their scope is an entire subject.
For example, for sharks, the item list is List of sharks and it presents shark species. A general topics list on sharks is the Outline of sharks, and its scope is everything about sharks.
In the page history for any page, click (prev) (#9 on the image top right—click on the image to see a larger version) to see the changes for any version from the one just before it. To compare a series of versions, just click any two radio-buttons to select the set of versions, then click the Compare selected versions button (this only works if you have JavaScript enabled).
You should be presented with a screen that shows you which words have been removed and which ones have been added (affected words are highlighted in red). You always can revert to an earlier version by selecting it from the history, editing and saving it. We call these "diffs" because the URL has the word "diff" in it. Diff is short for difference.
