Metastasis:1. This term refers to the mechanism through which cancer cells travel from their original site as a primary tumor to other parts of the body.2. It also describes the cancer that results from this spread. For instance, an individual with lung cancer may develop metastasis in the brain, while someone with another form of cancer might not experience any metastases. The process of metastasis requires cancer cells to gain two key capabilities: the ability to move more freely and to invade other tissues. The cells that metastasize are essentially the same as those in the initial tumor. So, if cancer starts in the lung and spreads to the liver, the cancer cells found in the liver are still lung cancer cells. However, these cells have developed increased mobility and the ability to infiltrate other organs.The word "metastasis" comes from the ancient Greeks, who used it to mean "removal from one place to another." The plural form of "metastasis" is "metastases."The adjective "metastatic" is often used with specific cancer names to indicate that the cancer has spread from its original site, thus becoming metastatic. For example, "metastatic melanoma" refers to melanoma that has extended beyond the skin to reach distant organs.