Undo
Undoes last performed action.

Redo
Redoes last performed action.

Cut
Cuts selected text

Copy
Copies selected text.

Paste
Pastes content currently in the clipboard.

Select All
Selects everything in the currently open file.

Swap header/source
Navigates to the file corresponding with the currently open header (.h) or source (.cpp) file. These pairs are often used in classes, and this button will make switching between declaration and definition easier.

Insert
Inserts templates which are added by default. One can also add items in the Tools >> Editor Options >> Code Insertion tab. More information about creating items can be found there.

Toggle Bookmarks
Inserts a bookmark mark to the currently focussed line, making it easier to find by sight and by Goto Bookmarks. Handy for finding class members in huge source files. When a bookmark is already inserted at the current line, it is removed.

Goto Bookmarks
Goes to the selected bookmark placed by Toggle Bookmarks.

Comment
Comments selection with single-line comments (//).

Uncomment
Removes first occurence of '//' from every line selected.

Toggle Comment
Uncomments if whole selection is commented, else comments.

Indent
Indents selected lines by a single tab. If nothing is selected, a tab is inserted. If only (portions of) one line are selected, the selection is replaced by a tab.

Unindent
Removes first occurence of 'tab' (\009) from every line selected.