Unlike other cancers, the vast majority of skin cancers have no potential to spread to other parts of the body (metastasize) and become life-threatening. There are two major types of skin cancer: basal cell carcinoma (the most common) and squamous cell carcinoma (the second most common). Melanoma is also a form of skin cancer but is far less common, though more dangerous, than the other two varieties.
The definition of backfill is material used to refill a hole, usually what was previously dug out of the hole. Dirt and gravel are examples of backfill. Backfill is defined as to return soil and other materials to a hole after it was dug.
Backgouging: The removal of weld metal and base metal from the weld root side of a welded joint to facilitate complete fusion and complete joint penetration upon subsequent welding from that side. Backhand Welding: A welding technique in which the welding torch or gun is directed opposite to the progress of welding. Backing Gas: Backing in the form of a shielding gas employed primarily to provide a protective atmosphere.