Precise values of the Z resonance cross sections and lepton pair forward-backward asymmetries are measured from a sample of 1.3 million Z decays into hadrons and charged leptons taken with the ALEPH detector at LEP. A silicon-tungsten luminosity calorimeter was installed in ALEPH in 1992, permitting the determination of the absolute luminosity to a systematic precision of 0.15% (experimental) and 0.25% (theoretical). This is combined with a better understanding of the hadronic event selection and an improved tau pair selection. Including the ALEPH results of the past three years one obtains σ{/h 0} =(41.60±0.16) nb, and R l =20.69±0.09. The corresponding number of light neutrino species is N v =2.983±0.034. The lepton pair forward-backward asymmetry is used to derive the ratio of vector to axial-vector couplings of leptons: g {/V 2}(M{/Z 2})/g{/A 2}(M{/Z 2})=0.0058 ±0.0011. An application of these results to constrain one model with extra Z bosons is presented.
