Computers function pretty much the same way that we do. Like us, they too need a place to store information. The same goes for your smartphones. There are three types of storage: primary, secondary, and tertiary. Among these, only the first two are widely and commonly used.

If compared to us, the primary storage is much like our short term memory (STM). It’s the memory that a home cook uses to remember what she needs in the storage room and forgets about it when she’s back in the kitchen after fetching what she needed. In other words, it’s a temporary memory. The secondary storage, on the other hand, is what is known to be the lasting memory. Let’s take a closer look at each of them.

Primary storage is basically the internal storage of your computer or smartphone. You will recognize them as the RAM or random access memory in your device’s setting.

Primary storage, which is also referred to as internal memory, is accessed by a computer’s central processing unit (CPU). It is usually the fastest and most expensive type of memory in the computer. Primary storage uses random-access memory (RAM), cache memory, or some other specialized hardware to store data while the computer is powered on. When power is removed, RAM is wiped clean. The volatile nature of RAM means that additional storage devices are needed that continue to work when a computer is powered off.


Secondary storage is what is mostly known as external storage drives. They are the “outside” drives used to store data with the exception of the hard drive. The hard drive in your device (computer or laptop) is built within the device. But it does not count as primary for the reason that the CPU cannot access it.

Secondary storage on a computer is provided by non-volatile devices such as hard disk drives. Even though a hard drive may be housed within a desktop or laptop, it’s not considered to be primary because it’s not accessed directly by the CPU. Data stored on hard disk drives and most other types of secondary storage devices is organized according to a file system. This type of storage is slower than primary storage, but it’s also cheaper.


Tertiary storage, the lesser-known and used storage, is so because it is only used for massive amounts of data including old data that has to be stored. It is slow and involves a robotic instrument to transfer data.

Tertiary storage is a third type of storage not typically found on a personal computer. This kind of storage device consists of high-capacity archives designed to house massive amounts of data on mountable media such as optical discs. The device typically includes a robotic arm or another mechanism that locates media containing specific data and transfers it from a storage location to a drive where the contained data can be accessed.


What used to be just the internal hard drive now has a brother – the external hard drive. Many are finding the advantages of an external hard drive mainly because of its spacious storage. CDs and DVDs are still around but they are less likely used because modern laptops especially small ones have bailed out on the disk reader/writer drive. Flash drives or commonly known as USB are the more preferred medium of portable storage as well as memory cards.

The average personal computer user mainly comes into contact with secondary computer storage devices. These include an internal hard drive and external drives that are typically connected via a standard interface like a USB cable. In the past, many computers came equipped with a drive to read and write CDs and DVDs. Today, this type of disc drive is more often connected as an external device, along with Blue-ray disc drives.

Flash drives, also known as thumb drives, have replaced CDs and DVDs as a portable storage medium. They are more compact and connect through a USB port rather than requiring a special drive. Memory cards used in digital cameras are also examples of secondary storage devices. The data stored on the card can be transferred to a computer using a built-in card reader or a reader connected via USB.


Data storage is a big deal. A lot of storage options are available now compared to a few decades back. If your storage devices like your hard drive are giving you a hard time, don’t worry. Our hard drive recovery service can more than help with that.