The buttons on the toolbar at the top of the µTorrent interface allows you perform some basic functions, most of which apply to the currently selected torrent(s). The order of the list here reflects the order of the buttons in the toolbar. If you are unsure, you can place your mouse cursor over a button, and a tooltip should pop up providing the description of the button. The toolbar's visibility can be toggled by selecting "Options" then "Show Toolbar" in the main menus, or by pressing F4 on the keyboard.