Kira902 Can you tell me the answer in a simpler language please?
The Chromium source tree can be built with various options. Some options that improve security use a bit more memory and run a little slower. Chromium builds for desktop/laptop PCs turn those on, but some Chromium builds for phones do not, because phones have less memory and smaller batteries. The cited text says that Vanadium turns some of those options on.
Keeping a full list of differences between Vanadium and other Chromium browsers up to date would be a lot of work, so that web page does not contain a full and up-to-date list.
Please note that I do not speak for the GrapheneOS project.