Defined Names

<definedNames>
  <definedName name="FMLA">Sheet1!$B$3</definedName>
  <definedName name="SheetLevelName" comment="This name is scoped to Sheet1"
    localSheetId="0">Sheet1!$B$3</definedName>
</definedNames>

Defined names can be used in place of cell references in formulas. For example, instead of using B3+1 to add 1 to the value that's in B3, one could define a name, as in FMLA, and assign it to B3. Then FMLA+1 can be used to perform the calculation.

Names can be defined and assigned to a cell location or range or to a formula or constant value. Names can be referenced in formulas. Names can be scoped to either the entire workbook (default) or just the local sheet. Names scoped to the local sheet cannot be referenced from other sheets. Names scoped to the workbook can be referenced from any sheet.

Defined names are actually stored in the workbook part, but are discussed here in the context of the sheet because they are so closely related to cells and formulas.