What is an Algorithm?

An algorithm is mathematical “logic” or a set of rules used to make calculations. Starting with an initial input (which may be zero or null), the logic or rules are coded or written into software as a set of steps to be followed in conducting calculations, processing data or performing other functions, eventually leading to an output. Google "search" is a great example of an algorithm at work. A searcher enters (or voice commands) a search, Google supplies that searcher with a relevant result using their complex algorithm.  

Teradata Take: Within the context of big data, algorithms are the primary means for uncovering insights and detecting patterns. Thus, they are essential to realizing the big data business case.