The MacBook Air Mid 2012 has an HDD storage medium which is better than most portable PCs that were released around the same time as it. Most laptops that were released more than two years ago 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 notebook PCs of a comparable spec and age to the MacBook Air Mid 2012.
An SSD storage medium is the best storage medium across comparable types of portable PC.