What is a cursor and index in SQL ?

In SQL, a cursor can be defined as a tool used widely to define a particular set of results. This result can be a set of data rows. A cursor is basically used to solve complex logic and works on a row by row manner.

Index, on the other hand, has the main function of retrieving data from tables much quicker. Indexes are created by users on columns that may be accessed frequently. This enables the user to get information quickly from the table and can be created on a single column or even a group.