system
Given the following post, respond as if you're commenting on Reddit:
human
I cannot grasp the concept of the 4th dimension can someone explain the concept of dimensions higher than 3 in simple terms?
gpt
To understand the 4th dimension, look for the similarities between the lower dimensions.

0 dimensions, means no height, no width, no length.

In the first dimension we can only have one line. 'Creatures' on this line can be longer or shorter, but never wider or taller. there can only see down that one line, so when they come close to one another, they don't see each other's length, just the front or back tip, it would look like a point. To them, that one line is their whole universe, nothing else could exist. We in the 3d world know that when you take one line, and you stack a number of parallel lines next to it, you create width or a second dimension.

For the second dimension, imagine a sheet of paper, by itself, it has almost no thickness, and for our purposes let's say it has no measurable height. 'Creatures' in the 2d world can move along that paper, front to back and side to side but they have no height, so when they see a wall, or another 2d being it looks like just a line, though in reality it is a shape, they have to move around that shape to see it's other dimensions because they cannot get off that sheet to see the shape from above. To them, it is their whole universe, nothing else could possibly exist,  But if you put enough sheets of 2d paper on top of each other, you create a stack which has height, a 3rd dimension.

Seemingly, a 4th dimension would all also be a series of 3 dimensional worlds stacked next to each other.. Which is why some people define time as being the 4th dimension, since it is an infinite series of 3d 'moments' stacked right next to each other.

For further information watch flatland. It goes into concepts like 1 dimensional beings only being able to percieve the portion of the 2d entity that was within their line of sight (a point), and similarly the 2d being could only see a slice of the total 3d being, the part that was in their line of sight within their 2d world. Similarly we would only percieve a slice of the total 4d being that interacts with us. 

But some believe that since we move along a timeline (though we do not have control of our movement) we are all 4d beings, only able to see a slice of each 3d moment of the other 4d beings we interact with. This follows with the concept that 1d beings, that would live in a 1d world could only travel on a line, and only see the point(0d) in front or behind them. And though 2d beings can travel through their 2d world in both dimensions, their perception of each other and the would would only be lines (1d). 3d beings would only see in 2d as they move throughout their 3d world. And 4d beings would move through 4 dimensions (height, width, length and time) but only be able to percieve 3 dimensions.

On the other hand, our ability to percieve 3 dimensions in one frame of time is due to our having 2 eyes, sort of a biological hack that gives us limited 3d perception. Seems to me, it's more like we percieve in 2 dimensions and have evolved a system that makes that not as big of an issue as it could be.

Edited for clarity/added info.