The Medium Resolution Imaging Spectrometer (MERIS) component of the Envisat ground segment is introduced, outlining the characteristics of the MERIS products in terms of their availability in time, spatial scale and coverage. The definition of processing levels and the overall philosophy of the design of the data products is presented. It will be possible to order MERIS data products consisting of different geophysical parameters depending on the surface type encountered. In addition, mixed level products consisting of surface leaving radiances, reflectances and geophysical parameters will be available from the same product. These geophysical parameters are briefly described.