Dielectron measurements in pp and Pb-Pb colllisions with ALICE at the LHC

The production of low-mass dielectrons is one of the most promising tools for the investigation of chiral symmetry restoration and thermal radiation from the QGP created in heavy-ion collisions. To single out the signal characteristics of the QGP, it is crucial to understand the primordial e(+)e(-) pair production in vacuum, i.e. in inelastic proton-proton (pp) collisions. Low-mass dielectrons have been measured with ALICE at the LHC in pp collisions at root s = 7 and 13 TeV, and in Pb-Pb collisions at root s(NN) = 2.76 TeV. An overview of the results on dielectron production is presented, together with their implications for the direct-photon and heavy-quark production