Searching for one item in a list or matrix of data (the table). Table lookups are used in countless operations to obtain a value or set of values such as retail and wholesale prices, product descriptions, street addresses, network routes, IP addresses and machine addresses. For example, in data entry validation, table lookups are used to acquire the valid range of values for each item entered.|
Software or Hardware
Table lookups are mostly performed by routines in software. However, to speed up operations, especially in networks, they can be performed in hardware. For example, routers and switches may have table lookup circuits for faster packet routing. See table, address resolution and routing protocol.