Differentiate resonator and filter characteristics

Resonator gives a s-parameter characteristic similar to a bandpass filter, so how does it differ from a bandpass filter?

Filters have resonator circuits, placed across the path (parallel) and / or in the path (series). As the frequency gets higher, they may take on unfamiliar forms, but the key thing is what they do, and whether they are connected across the circuit (shunt) or with the circuits (in series)

Consider a inductance in series with a capacitance. At the resonant frequency, this combination looks much like a near short-circuit. If this were used to couple one tuned stage onward to the next, it would have a high impedance for all frequencies except the wanted ones in the band, which it lets through.

Consider a inductor in parallel with a capacitor. This is also known as a "tank" circuit, though I am not sure why. This combination tends to look like a short circuit all the time, except at resonance, when the impedance is very high. If this were connected across the circuit (shunt mode), it would short-circuit all frequencies except the wanted ones, for which it would develop a voltage across the combination at resonance.

Various clever combinations of these parts can go to make up a complete filter. If you search keywords, you will find there are many classes of filters, and many forms of construction.

So - your resonator, depending on the way it is connected to present it's inductance-capacitance combination, could well be a bandpass filter.