Lifetimes, semileptonic branching ratios of B-hadrons and |Vcb| estimation

The lifetimes and the semileptonic branching ratios of the different b-hadrons are reviewed. The different methods to measure the lifetimes and the branching ratios are compared. The branching ratio for b → v + X from the L3 experiment is presented. These measurements result in an update of the KM — matrix element | V eb |.