Menus are sometimes hierarchically organized, allowing navigation through different levels of the menu structure. Selecting a menu entry with an arrow will expand it, showing a second menu (the sub-menu) with options related to the selected entry.
Torsion springs are normally mounted horizontally above the opening of your garage door. When you pull the door down, cables attached to the bottom corners actually force the springs to wind up, in turn energizing the system.
When you open your garage door, with or without a garage door opener, the bulk of the work is actually done by the counterbalance, a system of springs, pulleys, cables, etc., that make it possible for your garage door to open and close easily.