Type Alias Address

Address:
    | string
    | ICellRange
    | IRange
    | Readonly<Partial<IRange.FixableCoords>>
    | ICell.Address
    | FormulaError.Ref

This is either:

A string that can be parsed into a CellRange (e.g. 'A1:B2') or a named range.
Another ICellRange
An IRange
Partial IRange.FixableCoords