Grass

Grass is a style of map in Trackmania Nations Forever, which uses grass as its surface. It is a very simple style - these often place obstacles on the grass to avoid, making for a challenge, as grass has the least grip of all the surfaces.
Trackmania Nations Forever does not have many grass blocks in comparison to the other surfaces, such as the road. For this reason, players soon started combining grass tracks with other styles of map - one of the most common being Grass-LOL. Due to the ubiquity of these maps in comparison to true grass maps, many new players often refer to all grass-fusion maps as grass maps, which is incorrect. A true grass map is played entirely on grass (with the exception of the start and finish), and features grass checkpoints as well as obstacles such as trees; grass-fusion maps often have parts that resemble grass maps, but other sections that are more resembling of other styles.
It is very important to not mix up true Grass maps with grass-fusion maps, as this can be a huge blow to one's reputation in certain circles of the community, especially in areas centred specifically on the style. Enthusiasts of Grass-style maps see their most-liked style get mischaracterised very often, and it is offensive to them.