What is the importance of Fill Factor?

Answer:

A Fill Factor is a specification done during the creation of indexes so that a particular amount of space can be left on a leaf level page to decrease the occurrence of page splits when the data has to be accommodated in the future.

When an index is created or rebuilt, the Fill Factor value determines the percentage of space on each leaf-level page to be filled with data, reserving the remainder on each page as free space for future growth.

Fill Factor specifies a percentage that indicates how much the Database Engine should fill each index page during index creation or rebuild.Fill Factor is always an integer valued from 1 to 100. By setting the Fill Factor value, we specify the percentage of space on each page to be filled with data, reserving free space on each page for future table growth.Specifying a Fill Factor value of 70 would implies that 30 percent of each page will be left empty, providing space for index expansion as data is added to the underlying table.The empty space is reserved between the index rows rather than at the end of the index.

The Fill Factor option is designed for improving index performance and data storage.