Index fragmentation can be remedied by either reorganizing an index or by rebuilding an index. Refer to SQL Server documentation ...

Index fragmentation can be remedied by either reorganizing an index or by rebuilding an index. Refer to SQL Server documentation for details on how to manually detect and repair fragmented indices. This job should be run outside your normal SQL Server maintenance window, during off-peak hours, as query and crawl performance will be adversely affected. Do not run this job during farm backup/restore/upgrade. Disable this job if your SQL database mirroring latency is excessive.