A cursor is a temporary work area in a database management system (DBMS) that is used to store and manipulate the data retrieved from the database. A cursor is a database object that is used to process and manage the data rows returned by a SELECT statement, one row at a time. Cursors are used to enable the program to process and manipulate the data in a flexible and efficient way, and to enable the program to perform various operations on the data, such as fetching, updating, inserting, and deleting.

There are two types of cursors in a DBMS: implicit cursors and explicit cursors. Each type of cursor has its own specific characteristics and use cases, and they are used in different scenarios and contexts. The following is a brief overview of the main aspects of implicit and explicit cursors in a DBMS:

• Implicit cursors: An implicit cursor is a cursor that is created and managed automatically by the DBMS, and it is used to process and manipulate the data rows returned by a SELECT statement. An implicit cursor is created and used internally by the DBMS to process the data rows, and it is not visible or accessible to the programmer. An implicit cursor is used to process the data rows in a sequential and linear fashion, one row at a time, and it does not allow the programmer to control or customize the cursor behavior.
• Explicit cursors: An explicit cursor is a cursor that is created and managed by the programmer, and it is used to process and manipulate the data rows returned by a SELECT statement. An explicit cursor is created and used by the programmer to process the data rows, and it is visible and accessible to the programmer. An explicit cursor is used to process the data rows in a flexible and customized way, and it allows the programmer to control and customize the cursor behavior, such as opening and closing the cursor, fetching and updating the data rows, and handling and raising exceptions.

Implicit and explicit cursors are used in different scenarios and contexts, depending on the requirements and the needs of the program. Implicit cursors are used when the program does not require any control or customization over the cursor behavior, and when the program does not need to handle or raise any exceptions. Explicit cursors are used when the program requires control or customization over the cursor behavior, and when the program needs to handle or raise exceptions.

Overall, cursors are a powerful and essential tool in database management and programming, and they enable the program to process and manipulate the data in a flexible and efficient way. Cursors are used to enable the program to perform various operations on the data, such as fetching, updating, inserting, and deleting, and they are an essential component of any DBMS.