The Index property is read-only. The Index property is 0-based, so the first added element has the index 0, the second one has the index 1, and so on. You can use the Index property to identify the serie using the Item property or other propertyies. Use the Position property retrieves or sets a value that indicates the position of the serie. Use the Key property defines the identifier of the serie.  The Name property specifies the name of the chart serie which is visible in the legend. The Type property specifies the type of the serie (the way the data is represented). The Remove method removes a specific member from the Series collection, giving its identifier. The Clear method clears all series of the control. The Item property seturns a specific Serie of the Series collection, giving its identifier.