what are "bookmarks"

[zetaz]

Hello
Thank you for this wonderfull software...
i can't find informations in the manual or help file about "bookmarks". (generally speaking, i know what is a bookmark)
what is the difference with filter or search history ?
where can i found a documentation of this feature ?
thank you

[NotNull]

What is the difference between a filter and a bookmark and when should use which ?