Final answer:
A keyword has a predefined meaning in Oracle 12c, serving a specific function or purpose that the Oracle database language recognizes and interprets. Keywords are essential for SQL operations such as data retrieval and modification.
Step-by-step explanation:
A keyword has a predefined meaning in Oracle 12c. Among the listed options, a keyword is what has a specific, predefined function or purpose in the Oracle database language, which is understood and interpreted in a particular way by the system. Keywords in SQL, which is the querying language used by Oracle, include words such as SELECT, INSERT, UPDATE, DELETE, FROM, WHERE, etc. These terms have special meanings and they are reserved for performing specific operations in database management. For example, SELECT is used to retrieve data from a database, while UPDATE is used to modify existing data. Using these keywords correctly is crucial for creating effective SQL queries and for the overall management and manipulation of data in Oracle 12c.