What Are the True Nature and Meaning of Extra Dimensions?

[MartianVision]

I'm a little confused by extra dimensions. People seem to say different things about the 'extra dimensions. Everyone seems to say that there are 3 basic dimensions (width, height, depth), however some people say different things about what additional dimensions are, just wondered if someone can clear it up.

Is a fourth dimension time, and the fifth, sixth seventh etc. the different dimensions related to string theory, or are the extra dimensions more geometrical, such as this image:
http://www.dimension1111.com/images/dimensions1.png

Or am I just getting completely muddled up?

Sorry if I didn't really explain it too well, I'm terrible at explaining myself lol, and sorry if it's in the wrong forum.

 

[haael]

The picture you've given shows projections of higher-dimensional figures. Yes, they are "geometrical" and look exactly like that. This is a stage in learning about higher dimensions, but don't get stuck with it. Keep learning.

 

[gabriel.dac]

We live in a 4D universe if you consider time as a dimension. According to special relativity there is no reason it can't be a dimension as well