Resonance structures are usually known as the sets of Lewis structures describing the delocalization of electrons in a polyatomic ion or a molecule.
It is a manner of describing the bonding in particular molecules or ions by adding many contributing structures which are basically called canonical structures or resonance.
All the hybrid structures should be equivalent in nature to define resonance stability, but none of them independently describes the whole property of any given system.
Resonating structure of :
There is a total of three true resonating structures that can be drawn for .
Among them in the first structure, all atoms have a formal charge of zero.
for the next structures, S has a formal charge of +1 and one of the O atoms has a formal charge of -1.
However, for the last structure,S has a formal charge of +2 and two of the O atoms have formal charges of -1, and these three are known as the most stable structures.
Hence, the resonating structure of has been shown above.