Drag and Drop
This is a fast way to copy file(s) from one folder to another, or from a folder to a list of files displayed by a program.
Start by opening the folder holding the file to be copied. Next, depress your left mouse button while the mouse pointer is over the file's icon. Now use your mouse to drag the icon to its destination (either another folder, or a list of files displayed by a program). Finally, release your left mouse button.
You can also copy more than one file at a time. To select multiple files, simply hold down one of the <Ctrl> keys on your keyboard while clicking once on each file's icon with your left mouse button. When selecting the last file, don't release your mouse button, but keep it depressed while dragging the file icons as before.