Climbing grades
In the climbing world multiple different systems are used to deternime the difficulty of a climbing route. the two systems used the most are the font-scale and the V-scale, see figure 1. On both of these scales a higher number means that the route is harder.

Font-scale
The font-scale uses letters and a + or - in combination with numbers. The letters go from a-c with a being easiest and c being hardest, these can then be further classified by adding a + or -. with a + it is harder and - softer. As an example: a 6b is harder than a 6b- but easier than a 6c.

V-scale
The V-scale is mainly used in the americas and is a broader descripttion of climbing grades, with one V-grade usually containing multiple font-grades

Alpine climbing grades
For alpine climbing and mountaineering there are also differnt grades of difficulty. First there are the french alpine grades going from F, Facile, tot ED, extremely difficult. Secondly there are the UIAA, Union Internationale des Associations d'Alpinisme or international climbing and mountaineering foundation, grades which count up from 1 with a higher number indicating a harder route. the grades and conversion between them can be seen in figure 2.

French alpine grades
The french alpine grades are, in order of difficulty, called: F, facile or easy. PD, peu difficile or somewhat difficult. AD, assez difficile or fairly difficult. D, difficile or difficult. TD, tres difficile or very difficult. ED, extrement difficile or extremely diffucult. These grades also have in between grades marked with a '+' for slightly more difficult and '-' for slighly easier routes.

UIAA climbing grades
The UIAA climbing grades were devoloped before the introduction of modern sport climbing and the sport climbing grading, for example font-scale. The grades are denoted in roman numerals from I-IX however grades aboce VIII do not have a literal defination anymore.