In some very obvious position (right after Welcome) the manual should have a Glossary or set of Definitions especially for some of the more nebulous terms. Two in particular are needed because the terms mean different things when used in different programs or environments.
Widgets - are the graphical elements (menu text or icons) on which the user can click to perform or activate whatever the word or icon represents. Widgets are NOT the tool or action, they the GUI that causes the tool to activate or the action to happen.
DockWidgets - [I have no idea what this means which is why I make this suggestion]
Other terms - etc