Lookup table
ARRAY DATA STRUCTURE THAT REPLACES RUNTIME COMPUTATION WITH A SIMPLER ARRAY INDEXING OPERATION
Look-up table; Look up table; Look-up; Lookup; VLOOKUP; Table (computing); Table lookup; XLOOKUP
In computer science, a lookup table (LUT) is an array that replaces runtime computation with a simpler array indexing operation. The process is termed as "direct addressing" and LUTs differ from hash tables in a way that, to retrieve a value v with key k, a hash table would store the value v in the slot h(k) where h is a hash function i.