Ablation refers to the removal or destruction of material from an object or tissue, often by vaporization, chipping, or erosive processes. It has different meanings and applications depending on the context:

1. Medical Ablation: In medicine, ablation is a procedure used to destroy abnormal tissue. For example, cardiac ablation is a treatment to fix irregular heart rhythms (arrhythmias) by creating tiny scars in the heart tissue to block faulty electrical signals and restore normal rhythm. Ablation therapy can also be used to treat tumors or other abnormal tissue in various parts of the body using heat, cold, lasers, or chemicals. It's minimally invasive compared to open surgery.
2. Biological Ablation: This involves removal of a biological structure or function, such as genetic ablation (gene silencing) or cell ablation (destroying individual cells).
3. Glaciology Ablation: This refers to the processes that remove snow, ice, or water from a glacier or snowfield, such as melting, sublimation, or erosion by wind.

In summary, ablation generally means the removal or destruction of a particular material or tissue, with specific types related to medical treatments, biological experiments, or natural processes like ice melting.