When you are typing on the computer, you get (a black flashing line that shows you where you are typing). The black flashing line is called "the cursor." (It is also called "the text cursor," or "the insertion point.")
To position the cursor "exactly" where you want it, it is often easier to use the arrow keys on the keyboard, rather than the mouse.
You can also make the cursor move faster. If you hold an arrow key down (try the Left arrow key or the Right arrow key), the cursor will keep moving quickly.
If you hold the "Ctrl" key (called the "control" key) down, and then "punch" the Right arrow key or the Left Arrow key, the cursor will jump to the next "word" instead of the next letter. Every time you punch the arrow key once, with the Ctrl key held down, it jumps to the next word.
If you hold the "Ctrl" key down, and then "hold down" the Right arrow key or the Left Arrow key, the cursor will jump quickly from word to word. This is even faster than holding an arrow key down without the Ctrl key.
If you would like more information on working with the cursor, see this article "Highlighting With The Keyboard Or The Mouse - For Erasing More Stuff."