**What is 3D?**

Humans can see anything around them in 3D because we have 3D perception, also known as depth perception. This is how you can tell if a mountain is a long way away. When we look around us, each of our eyes produces a two-dimensional image, which our brain combines with the other to create a three-dimensional visual experience. By peering through a small hole with one eye, people who can only see out of one eye can see in 3D.

You may have gone to the movies to see 3D movies using special 3D glasses. By displaying two different images at the same time, these glasses make 2D visuals on the screen appear 3D. Each of these images is displayed to one eye at a time, resulting in slightly different images being seen by each eye, which are then combined in the brain to form one image.

A square plane, for example, can be described by either of the two axes in the coordinate system, namely the x-y plane, the y-z plane, or the z-x plane, however the presence of a cube requires all three axes. Only the data taken from all three axes may be used to calculate the cube’s volume.

**What is 4D?**

Space with four spatial dimensions is referred to as 4d space. There are three of them: height, width, and depth. Obviously, this creates a three-dimensional space. 4d space is comparable to 3d space, with the exception that it possesses an extra dimension that we 3d beings are unable to see. As a result, a 4d space has four dimensions: height, width, length, and the elusive fifth dimension, x.

Do four-dimensional beings exist? The basic answer is that no one can respond to that question. Although some theories, such as String Theory and M-Theory, leverage the possibility of additional dimensions to explain our universe, I imagine the concept of a 4d space is hotly contested in physics labs.

The Tesseract is an excellent example of how to comprehend the fourth dimension. The presence of a cube in the fourth dimension is known as tesseract. The tesseract is generated when a cube is believed to be extruded in a direction perpendicular to the current three-dimension.

The tesseract from a three-dimensional perspective is depicted in the gif below. We find it tough to perceive since we can only detect in three dimensions. Scientists are putting in their best efforts to bring this abstract to life, which may take some time.

**Difference Between 3D and 4D**

- Three-dimensional space refers to the placement of a point in relation to three co-ordinates (axes). Time is introduced to the three-dimensional space as an additional virtual axis in the fourth dimension, which is a mental one.
- The dimensions of a three-dimensional space are length, width (breadth), and height. As a fourth dimension, time is introduced.
- We live in a three-dimensional universe. Einstein’s general theory of relativity, which is still an abstract, was used to define the concept of four dimensions.
- A cuboid, cube, sphere, or any geometrical illustration of three-dimensional space can be used. A classic example of fourth-dimensional space is the Tesseract.
- Additive manufacturing is a good illustration of this. 3D printing is the process of adding material to a perpendicular base. 4D printing is defined as when a 3D print begins to react to changes in the surroundings.

**Comparison Between 3D and 4D**

Parameter of Comparison | 3D | 4D |

Parameters | Length, breadth(width) and height | Length, height, width(breadth) and time |

Visualization | It’s possible to sense and experience | Cannot be easily recognized |

Origin | Beginning of the seventeenth century | Late eighteenth century |

Proof of Existence | Three-dimensional space has been demonstrated in both theory and practice. | The fourth dimension is a concept that has yet to be proven in practise. |

Mathematical Parameters | X, Y and Z axis | It is made up of four dimensions, with time acting as a virtual axis. |

Example | Cuboid | Tesseract |