In severe cases, the viral infection causes a high fever, bleeding into the skin, and necrosis (death) of cells in the kidney and liver. The damage done to the liver from the virus results in severe jaundice which yellows the skin. Hence, the yellow in yellow fever..
filter definition: The definition of a filter is something that separates solids from liquids, or eliminates impurities, or allows only certain things to pass through. (noun) A Brita that you attach to your water faucet to remove impurities from you...
This term was used in UNIX systems and is now used in other operating systems. A filter is pass-through code that takes input data, makes some specific decision about it and possible transformation of it, and passes it on to another program in a kind of pipeline.