We will try to make this as short as possible for this is a large area to cover.
Based on current knowledge, everything is energy functioning in different frequencies. How does this form a car, or ourselves, or the air we breath? Very simple. There is a frequency array our world is built from. We know that in order for something to exist, it has to move. Let us explain this a bit: if a sub-particle is not moving, or otherwise not emitting a frequency, it does not exist. This is why the absolute zero is just theoretical, because matter would not exist without moving or emitting a frequency.
Like Einstein told so many times, the world exist only because there are referral points knowing of each other in the world. Let us take this to frequencies. We know that electromagnetic fields influence each other and when two fields are working on similar frequencies, they resonate with each other, creating a push or pull between each other. This means that two different things like our hands and a wall never really touch each other, we just feel so.
The understandable world is just this array of frequencies that resonate with each other. On the very edge are things like the neutrino that barely resonate with our array of frequencies, thus not having contact with our world.
This does not mean that other arrays cannot exist. An other array that contains much higher or much lover frequencies would simply not be perceived by our array, since these frequencies do not resonate. An example would be the light passing through glass, the light has high frequency, while the glass has low frequency. They having similar frequencies would mean that light could not pass glass.
Of course we must take in consideration the spaces between particles, the size of fields they create, etc.
Now particles exist in every dimension. A dimension is always the projection of a higher dimension. The only problem with this is that projection means data loss. To make this a little easier, lets take a bottle. If you put a bottle on a paper, and say there is a person in 2 dimensions on the paper viewing this bottle, the person will only see a circle and will not know what that is. For him, it could also be glass or a piece of wood.
Now this means that being in this dimension, we cannot image the 4th dimension, since we are made out of the 3rd dimension. We mean we cannot perceive it. It is possible to imagine it, also it is there, we know it from mathematics, but we cannot understand the extension of our array of frequencies in the fourth dimension, because we only see the circle that is the bottom of the bottle.
These views of the world let many things become possible, but are also logical and understandable. Since every person perceives the world otherwise, making things more simple is a way to create an image in many heads.
It is possible that people do not talk about these things, because they think it is too hard to understand.
Here is a video demonstrating how frequency affects shapes:
Dimensions: