What is the difference between euclidean geometry and hyperbolic geometry?
Euclidean geometry and hyperbolic geometry are two different types of geometry, each based on different assumptions and axioms. Here are some of the key differences between them:

1. Parallel lines: In Euclidean geometry, parallel lines never meet, and the sum of the interior angles of a triangle is always 180 degrees. In hyperbolic geometry, however, parallel lines can intersect, and the sum of the interior angles of a triangle is always less than 180 degrees.

2. Space curvature: Euclidean geometry assumes that space is flat, whereas hyperbolic geometry assumes that space is curved. In hyperbolic geometry, the curvature is negative, which means that the angles of a triangle add up to less than 180 degrees.

3. Distance: In Euclidean geometry, the distance between two points is the straight line between them. In hyperbolic geometry, the distance between two points is measured along the curve of the space, which is curved.

4. Geometry of circles: Euclidean geometry and hyperbolic geometry have different rules for circles. In Euclidean geometry, a circle is defined as the set of all points that are equidistant from a given center point. In hyperbolic geometry, a circle is defined as the set of all points that are closer to a given center point than a certain distance.

Overall, hyperbolic geometry provides an alternative model of space that is very different from Euclidean geometry. Hyperbolic geometry has many applications in physics, computer graphics, and other fields.
I didn't understand fully the 3rd one. Can you explain that again? What is this curve of the space?
Certainly! 

In Euclidean geometry, the distance between two points is simply the length of the straight line connecting them. 
However, in hyperbolic geometry, the distance between two points is measured along the curve of the space. 
This means that if you draw a straight line between two points in hyperbolic space, the line will actually appear to be curved, because the space itself is curved.

To help visualize this, you can think of the surface of a sphere as an example of curved space. 
If you draw a straight line on the surface of a sphere, the line will actually be a curve when viewed in three-dimensional space. 
Similarly, in hyperbolic geometry, the space itself is curved, which means that straight lines appear to be curved. 

I hope this helps clarify the concept!