Database Programming with PL/SQL 2-2: Recognizing PL/SQL Lexical Units Practice Activities Vocabulary Identify the vocabulary word for each definition below: An explicit numeric, character string, date, or Boolean value that is not represented by an identifier. Symbols that have special meaning to an Oracle database. Words that have special meaning to an Oracle database and Describe the purpose and use of each code segment and are ignored by PL/SQL. LEXICAL UNITS Building blocks of any PL/SQL block and are sequences of characters including letters, digits, tabs, returns, and symbols. IDENTIFIERS A name, up to 30 characters in length, given to a PL/SQL object.