Definition o Given an alphabet bet S, a pattern P of length m and a text T of length n, find if P is in Tor the position( s)p matches a substring of T, where usually m<<n o Considering the pattern P Ostring exact string matching O string with errors approximate string matching O regular expression regular expression matchingDefinition ⚫ Given an alphabet bet S, a pattern P of length m and a text T of length n, find if P is in T or the position (s) P matches a substring of T, where usually m<<n ⚫ Considering the pattern P string exact string matching string with errors approximate string matching regular expression regular expression matching