Define the following types of mining:
- long wall mining
- mountaintop removal
- pillar mining
- strip mining
- surface mining
- underground mining

Long Wall Mining: Longwall mining is a type of underground mining that involves extracting coal from seams that are quite thick and large. It is driven by a machine that penetrates walls to cut out the coal. Mountaintop Removal: Mountaintop removal mining is a type of surface mining where mountaintops are removed to reach coal deposits below them. The process involves blasting away the top of a mountain, extracting the coal with heavy machinery, and then dumping the waste material into nearby valleys. Pillar Mining: Pillar mining is a type of underground mining that involves extracting large amounts of coal from a coal seam in order to create a pillar that supports the roof. This type of mining is typically used in very deep seams. Strip Mining: Strip mining is a type of surface mining that takes place in areas with flat terrain. This is done by removing layers of soil and rocks to access the coal underneath. The layers are then piled up and graded to reclaim the land. Surface Mining: Surface mining is a type of mining that takes place on the surface of the land and involves removing surface materials such as soil and rocks to reach coal deposits below. Underground Mining: Underground mining is a type of mining that takes place below the Earth’s surface and involves digging tunnels and shafts to access coal deposits. It is typically used in deeper coal seams and mines.