The cursor on your screen can indicate two things: 1) where your mouse pointer is, or 2) where the next character typed will be entered in a line of text.
The mouse cursor is most often an arrow that you can use to point to different objects on your screen. When the cursor is over an object, you can click or double-click the mouse button to perform an action on that object (such as opening a program). The mouse cursor can change into other images, such as a small hand (when you roll over a link in a Web page), or an hourglass (when Windows is "thinking" so hard, it won't let you click on anything).
The text cursor is typically a straight vertical line or I-shaped object that flashes in a line of text. Typically, when you are typing a paper, the cursor will be at the end of the line, because you are adding new text to the uncharted white area of the page. However, if you want to insert a word or phrase somewhere else in a line of text, you can use the mouse cursor to click the position where you would like to insert the text. In most word processing programs, once you start typing, the text cursor continues to flash, but the mouse pointer disappears until you move the mouse again. This is to avoid "cursor confusion," since most people can't type and click on things at the same time.