What characteristic defines Double Data Rate (DDR) SDRAM?

Double Data Rate (DDR) SDRAM is designed to transfer data on both the rising and falling edges of the clock signal, effectively allowing it to operate at twice the speed of the system clock. This means that for each cycle of the system clock, DDR can complete two operations, which enhances the memory's bandwidth and overall performance. This characteristic sets DDR apart from traditional Single Data Rate (SDR) SDRAM, which only transfers data on one edge of the clock cycle.

The capability to double the data throughput without increasing the clock frequency is fundamental to DDR technology. Other options describe features that do not accurately capture the essence of DDR SDRAM or relate to other attributes not specific to DDR.