Dictionary

el_1 -> el_2

means subordination of el_2 element in relation to el_1 element, e.g. "Settings -> Program settings" means the option "Program settings", related to "Settings" menu.

double-click

quick double-click with the mouse left button on a given element

FAQ

It is an English abbreviation from Frequently Asked Questions.

click "something",

"using a key"

Set the mouse cursor over "something", and then press the mouse button and release it immediately. If no button is given it should be assumed that the left one should be used.

drop-down menu

This means menu related to an element of the program which appears after you click it using the mouse right button and disappears when you select the option you like.