Computers usually rely on hard disk drives, also known as HDDs, to store data permanently. The hard disks act as devices for storage that are often used to save and retrieve digital information, and that information will be needed later for future reference.

Hard drives are usually nonvolatile. This means that hard disks can retain data even when they are not connected to any power. The information you store in your hard drive remains very safe, and as it is, unless the hard drive is damaged or destroyed or someone interferes with it.

The information you store or retrieve is put in a random-access manner rather than a sequential access manner. This means that the blocks of data that you have stored can be accessed anytime that you want without going through other blocks of data.

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Parallel Advanced Technology Attachment (PATA)

PATA Hard Disk

PATA was among the first types of hard disks. It made use of the interface of Parallel ATA standard connect to computers. These drives provide a common technology of interface so that your hard drive connects and other devices to your computer. 

The data transfer rate can go up to about 133 MB/s, and along with this, a maximum of 2 devices can be connected to a channel of the drive. The motherboard uses two channels and has 40 to 80 cables of the wire ribbon that further transfer multiple bits of data simultaneously.

Serial ATA (SATA)

SATA Hard Disk

The SATA drives to transfer data faster than the PATA ones as it uses serial signaling technology. Furthermore, they are comparatively thinner than PATA drives. Along with this, there is a connection of data with 7 pins. 

The limit of the cable is 1 meter. The SATA disks do not share the bandwidth as the number of disk drives allowed is just one per SATA controller chip. Additionally, SATA drives consume significantly less power and require only 250 mV, while the PATA drives consume 5V.

Small Computer System Interface (SCSI)

SCSI Hard Disk

Next up is SCSI. These drives are very similar to IDE hard drives. SCSI drives can be connected to your computer, both internally as well as externally. Devices that you connect with a SCSI, in the end, have to be terminated. These drives are significantly faster compared to the above two mentioned drives.

Furthermore, these are very reliable, and the data stays safe in these drives. It is a great option to go for 24/7 usage and operations. Along with this, SCSI drives have better scalability and are flexible when it comes to arrays. Lastly, they are well adapted to store as well as move large data amounts.

Solid State Drives (SSD)

SSD Hard Disk

SSDs are the latest technology in the drive and computer industry. These do not consist of moving parts. Neither do they store the data using magnetism? Instead, what they do is make use of the technology of flash memory. 

Furthermore, they also use circuits that are integrated or devices with a semiconductor so that the data gets stored permanently or till the time they get erased. Some of the advantages are that you get access to data faster, it is less susceptible to shocks, lower access to latency and time, the durability is very high, and there is less usage of power.