In the hypothesis testing approach of Jerzy Neyman and Egon Pearson, a null hypothesis is contrasted with an alternative hypothesis, and the two hypotheses are distinguished on the basis of data, with certain error rates. Proponents of each approach criticize the other approach.
In geography, relief refers to the highest and lowest elevation points in an area. Mountains and ridges are typically the highest elevation points, while valleys and other low-lying areas are the lowest. Relief is essential to understanding the topography of an area.
Fold mountains are created by uplift and folding of tectonic plates as they move towards each other and collide. This is known as a compressional plate margin. An example is the Andes Mountain range in South America(Nazca Plate colliding with the South American Plate).