A stock market, equity market or share market is the aggregation of buyers and sellers (a loose network of economic transactions, not a physical facility or discrete entity) of stocks (also called shares), which represent ownership claims on businesses; these may include securities listed on a public stock exchange as well as those only traded ...
Redundancy is a system design in which a component is duplicated so if it fails there will be a backup. Redundancy has a negative connotation when the duplication is unnecessary or is simply the result of poor planning.
redundant (comparative more redundant, superlative most redundant) 1  Superfluous; exceeding what is necessary. ( 2 of words, writing, etc) Repetitive or needlessly wordy. ( 3 chiefly Britain, New Zealand, Australia) Dismissed from employment because no longer needed; as in rendered redundant.