An object type is a kind of data type. You can use it in the same ways that you use standard data types such as NUMBER or VARCHAR2.

Object types are composed of attributes and methods, eg

CREATE TYPE person_typ AS OBJECT (
  idno           NUMBER,
  first_name     VARCHAR2(20),
  last_name      VARCHAR2(25),
  email          VARCHAR2(25),
  phone          VARCHAR2(20),
  MAP MEMBER FUNCTION get_idno RETURN NUMBER, 
  MEMBER PROCEDURE display_details ( SELF IN OUT NOCOPY person_typ ));

Collection types are more like arrays, ie, one or more elements. Oracle Database supports two collection data types: varrays and nested tables