Musgrave demystified

Ever wondered what Lacunarity means in a Musgrave Texture Node? 

Does it have anything to do with lagunes?

No!

Imagine a basic noise texture.
Now divide its scale by, let's say, 2.0.
Repeat this a few times, let's say 7 times.
Add all 8 noise textures.

The number we divided the scale (in our case: 2.0) by is called:
Lacunarity. (So a Lacunarity of 1.0 always results in a single (basic) noise texture.)
The number of times we repeat the dividing of the scale (in our case 7) is called:
Octaves.
How strong the original noise texture is compared to the scaled versions is called:
(Fractal) Dimension.

Now you still don't know how to use the Musgrave Texture Node, but, you'll hopefully have a better idea.
And maybe you can now show off your knowledge at a party (although, what kind of parties do you go to, if you can impress people with this kind of.....)

Here's a small bonus:

In a Voronoi Texture Node, you can find something like a Manhattan Distance.

(There are many different ways to define a distance in mathematics, there even exists a distance definition, so that every point inside of a circle is its center!)

Imagine going 3 Blender Units to the right and 4 Blender Units up. Then you will have travelled a distance of 5 BU. (The square root of 3 squared plus 4 squared.)

The Manhatten distance you have travelled is 7 BU. ( 3 plus 4, you've guessed it!) Named after the streetplans of cities (maybe even Manhattan).