The following table defines the differences: Jitter, Noise, BER IConnect Focus Tx / System Cable, Backplane, system Signal source Tx TDR Application Serial  link characterization Cable, backplane, connector, package Active/passive device focus Active, Tx Passive, interconnect Typical measurements Jitter, noise Impedance, S-parameters BER DDJ and eye Additional capability Single S-parameter block Multiple S-parameter blocks FFE, DFE Equalization Pre-/de-emphasis Emphasis, FIR filters Fixture de-embedding Fixture de-embedding Channel emulation Multiple S-parameter simulation FIR filters Spice modeling