The Lenovo Yoga 2 has an HDD storage medium which is better than most notebook PCs of this age and type. Most 2 in 1 laptops that have been around for around the same time as it have an SSD storage medium. HDD is a traditional storage drive which stores the information on magnetic disks. HDD drives are slower than other forms of storage such as solid state drives (SSD) and flash drives.
An HDD storage medium is actually the worst storage medium amongst all laptops of a similar type and age to the Yoga 2.
An SSD storage medium is the best storage medium amongst similar types of notebook PC.