HOW TO DELETE A FILE
To delete a file you must first have it selected (highlighted in blue), by clicking on either its name or icon. Once the file is selected (highlighted in blue) you then have four main methods for deleting it. With the first method press the COMMAND keyboard down, and with it still held down, press the BACKSPACE keyboard key. Doing so will then place the selected file inside the TRASH folder; so technically it has been deleted (more about this will be explained later).
With the second method you don't need to select (left click on) the file. When you click over it using the right mouse button (right click), whilst the mouse pointer is over the file, a context (options) menu will appear whereby the file is then selected for you automatically.
When the context menu appears (above) move the mouse pointer down its menu items until it reaches and highlights in blue the menu-item called MOVE TO TRASH. From there keep the mouse pointer still, whilst it is over the highlighted menu-item called MOVE TO TRASH, and click the left mouse button. So you have clicked on the highlighted menu-item called MOVE TO TRASH in other words. This will then delete (move into the TRASH folder) the selected file (i.e. Research_Notes.rtf).
The third method requires the file you want deleting to be selected (as in Fig 1.0 above) so that its folder window becomes the active folder window and can therefore utilize the Apple Menu Bar menus (titles) and menu-items (menu options) at the top of the desktop screen. In other words, you are making sure the Apple Menu Bar menus (titles) and menu-items (menu options) correspond to the options available for the selected file (Research_Notes.rtf in this example) and its folder (the DOCUMENTS folder window). If the file is not selected and therefore not active the Apple Menu Bar menus and menu-items will be of no use simply because they will correspond to the folder, file or application that is currently active/selected instead.
Once the file you want to delete (Research_Notes.rtf) is selected, and therefore the active file, you can then click on the FILE menu (the title called: FILE) on the Apple Menu Bar.
Clicking on the FILE menu will reveal the FILE Menu-Items (Options) available for the active file (i.e. Research_Notes.rtf) and its active folder window (i.e. the DOCUMENTS folder). You now need to move the mouse pointer downwards (down the menu-items) until it reaches and highlights in blue the menu-item called MOVE TO TRASH. From there you keep the mouse pointer still, whilst it is over the highlighted menu-item called MOVE TO TRASH, and click the left mouse button. So you have clicked on the highlighted menu-item called MOVE TO TRASH in other words. This will then delete (move into the TRASH folder) the selected file (i.e. Research_Notes.rtf).
The fourth method uses the DRAG & DROP technique. This basically means you get hold of the file you want to delete, using the left mouse button, and physically move it (drag it) into the TRASH folder using the mouse pointer. To see what I mean; Click on the file you want to delete but do NOT let go of the click - Keep the left mouse button pressed down. Now move the mouse pointer towards the TRASH folder (Trashcan icon), with the left mouse button still clicked whilst on top of the selected file, so that you are now dragging (moving) the selected file along with the mouse pointer.
When the mouse pointer and file have reached the TRASH folder (Trashcan icon), so they are more or less hovering over the TRASH folder (Trashcan icon), let go of the left mouse button in order to DROP the selected file into the TRASH folder. This whole technique is known as DRAG & DROP, because you are dragging (moving) a file and dropping it into something. In this example, into the TRASH folder. The DRAG & DROP technique is also used with folder and e-mails.
The eagle eyed amongst you will have spotted the DELETE and ACTION buttons on the DOCUMENTS folder (window), but I purposely did not mention these as methods for deleting a selected file simply because they cannot be alternative methods if those button are hidden (switched off via folder customization). So don't rely on them being available on any folder's window in other words. If they are available though just click on them and then follow the above procedure to delete the selected file. The ACTION button was explained in the Create A New Folder section.
If you ever need to Undelete something from the TRASH folder (Trashcan) click on the Trashcan icon to open its folder, right click on the file you want to undelete and then click on the PUT BACK menu-item. This will put the selected file back in its original place (i.e. put the Research_notes.rtf file back inside the DOCUMENTS folder).
On the other hand; If you want to permanently delete the selected file, and everything else that is inside the TRASH folder (Trashcan), first right click on the Trashcan icon to bring up its context (options) menu and then left click on its EMPTY TRASH menu-item.
If you don't have a mouse with a right click on it, for whatever reason(s), you can always emulate the right mouse click - Press the CTRL (CONTROL) keyboard key down and with it held down then click the left mouse button. This will then bring up the context (options) menu for that application, folder or whatever.