Bit of a new question, but here goes. I'm familiar with futures contracts from a textbook perspective, just starting monitoring the Nymex Minis for Crude and Natural Gas. I thought initially that I would need to rotate through the near month contracts as time progressed, but was suprised to see the symbol codes help mentioning the continuous contracts. So, my question is, how exactly do these function, and what is their purpose? Is this something that exists purely for the sake of long-term monitoring/charting of the given futures contract (e.g. Crude mini), or does it function the same way as the monthly contracts (i.e. delivery occuring around a particular date for the given month). Thanks!