What are pseudo-columns? How can you use pseudo-columns in procedural statements? | PL SQL

 Pseudo-columns are not actual columns in a table but they behave like columns. They are used in SQL statements to retrieve specific information. PL/SQL recognizes pseudo-columns as a part of SQL statements but they cannot be used directly in a procedural language.
The following pseudo-columns are used in SQL:
=>    ROWID
=>    ROWNUM
=>    LEVEL
=>    CURRVAL
=>    NEXTVAL.