Libreoffice is open Source official software , that mean you can use it free of cost for office use like document edit, Spreadsheet editing and Presentation.
That mean you can use it as a alternate of Microsoft Office.
Microsoft Office is used of Word Processing, Spreadsheet editing , Presentation show but this is Shareware software (paid) .
If you don’t want to pay money for This kind of official software then use Libreoffice which is fully free.
