difference between two resonant frequency of antenna and dual band operation

Hello every one
I have confusion regarding the terms dual band operation of antenna(antenna can radiate at 2 different frequencies),
and the term "two resonant frequencies for antenna".
if a stacked patch antenna has two patches which are used to acheve greater BW. Will both the patches radiate at the two different resonant/centre frequency or ont same centre frequency?

If anyone having tutorial on the basic operation of stacked patch antenna, kindly share.

thanks

If is about a TX antenna, in almost all situations the dual-band antenna is feed by a single frequency at a time (one band) from the transmitter.
When is about RX, there is possible the dual-band antenna to receive two frequencies (two bands) simultaneous, as in LTE Advanced situation.
The term "two resonant frequencies of an antenna" refers to a dual-band antenna as a stand alone device, and not part of a system.