This is a basic stopper knot, to keep a rope from going through a hole or to reduce fraying at the end of a rope; however, the figure eight knot works better for that. Overhand knots are interesting mostly because they form the basis for many other knots:

• square knots are two overhand knots, executed as mirror images (right over left, then left over right; or vice-versa);
• granny knots are usually the result of screwing up the aforementioned square knot (two overhand knots tied the same way);

In ASCII art, an overhand knot tied on a single rope looks much like a pretzel:

```           ______  ______
/      \/      \
/   __   \  __   \
/   /  \   \/  \   \
\   \  /\   \  /   /
\   \/  \   \/   /
\  /   /\  /   /
\/   /  \/   /
___________/   /\__/   /\______
/       /        |
_____________/\______/\________|
```

Topologically equivalent, but a bit weirder looking:

```           ______________________
/                      \
/   __________________   \
|   /                  \   |
|   \  ______  ______  /   |
\   \/      \/      \/   /
\   \  __   \  __   \  /
\   \/  \   \/  \   \/
___________/\   \__/\   \__/\   \____
\       \       \       |
_____________/\______/\______/\______|
```

When tied with two ends (as you would if you were using it as the start of a larger knot), it looks like this:

```                (make bow here)

\   \  ______  ______  /   /
\   \/      \/      \/   /
\   \  __   \  __   \  /
\   \/  \   \/  \   \/
___________/\   \__/\   \__/\   \__________
\       \       \
_____________/\______/\______/\____________
```