"visual" mode is by default entered whenever non-text-area text is selected and left whenever it is deselected. It can be manually entered with
v;h hint mode/F7The default behaviour can be modified with :set visual{enter,exit}auto {true,false}.
The visual mode keybinds:
h,j,k,l,e,w,b moves the cursor and expands or reduces the selection0 expands or reduces the selection to the beginning of the line$ expands or reduces the selection to the end of the line= expands the selection successively until the whole web page is selectedo moves the (invisible) cursor to the other end of the selectiony yanks selected text to the clipboards and S searches for selected textSee ":help vmaps" to see all the binds.
The next page will cover the command mode.