Orbital and stellar parameters of symbiotic stars

This paper reviews current knowledge of symbiotic binaries, with special emphasis on their multifrequency observational characteristics, and basic parameters of the symbiotic system components. We start with a brief presentation of variable phenomena found in symbiotic stars. This is followed by a summary of the recent progress in determination of their orbital and stellar parameters. We also discuss basic properties of the symbiotic giants compared to single evolved giants as well as the nature of the hot component and its outburst evolution.