The KLOE detector at the DA$Phi$NE $phi$-factory has been operating in two periods from 2001 to 2006 and from 2014 to 2018 collecting a large sample of $phi$-meson decays. This allowed to perform precision measurements and studies of fundamental symmetries, and searches of New Physics phenomena. In this overview, the results of KLOE and KLOE-2 Collaborations are presented. The most recent results from the KLOE experiment are discussed, covering: the measurement of the running fine-structure constant $alpha_{em}$, the Dalitz plot measurement of $eta rightarrow pi^+pi^-pi^0$, the search of a U boson, tests of discrete symmetries and quantum decoherence.