Hard Disk Drives (HDDs) are a common type of non-volatile storage device that have been prevalent in the computing industry for decades. These drives store data on a set of spinning magnetic platters and use read/write heads attached to a mechanical arm to access the data while the disks spin. One of the key concepts with HDDs is that they are significantly slower than solid-state drives (SSDs), as they rely on the movement of the mechanical components to access data. However, their cost-per-gigabyte is typically lower, making them a more cost-effective choice for larger storage capacities. Another unique feature of HDDs is the use of caching, which uses a small amount of high-speed memory located on the drive to temporarily store frequently accessed data, thereby improving overall performance.

Solid State Drives (SSDs) are a newer type of non-volatile storage device that has gained popularity due to its superior performance compared to traditional hard disk drives. Instead of using mechanical components like HDDs, SSDs rely on NAND-based flash memory, which allows for faster read/write speeds and reduced latency. This makes SSDs an ideal choice for systems that require high-speed data access, such as gaming rigs or professional workstations. However, SSDs are typically more expensive per-gigabyte when compared to HDDs. SSDs are also known for their improved durability, as they are less prone to mechanical failures due to their lack of moving parts. Additionally, SSDs consume less power than HDDs, resulting in lower energy costs and increased battery life for mobile devices.

Serial ATA (SATA) is a standard interface for connecting storage devices, such as HDDs and SSDs, to a computer's motherboard. SATA was developed as a successor to the older Parallel ATA (PATA) standard and has many advantages over its predecessor. SATA is faster, more efficient, and supports newer technologies such as hot-swapping and native command queuing. The most recent versions of SATA, SATA III, provides data transfer rates of up to 6 Gbps (gigabits per second), whereas PATA was limited to 133 Mbps (megabytes per second). This improved performance allows for faster data transfers and reduced bottlenecking within a computer system. SATA cables are also smaller and more flexible, simplifying installation and improving airflow in computer cases.

Non-Volatile Memory Express (NVMe) is a modern storage protocol developed specifically for SSDs, which enables faster and more efficient communications between storage devices and a computer's system. NVMe takes advantage of the fact that SSDs do not have the same mechanical limitations as HDDs, allowing it to better utilize the full capabilities of SSD technology. By using a more streamlined command set and supporting more parallel operations, NVMe can provide significantly faster read/write speeds compared to SATA-based SSDs. NVMe storage devices typically connect via M.2 or U.2 interfaces, which provide direct access to a computer's PCIe lanes for maximum performance. However, NVMe drives often come at a higher cost compared to SATA-based SSDs but can offer substantial performance improvements, making it a popular choice for high-performance systems.

Redundant Array of Independent Disks (RAID) is a technology that combines multiple physical storage devices into a single logical unit in order to improve performance, redundancy, or both. RAID systems are used in various settings, such as enterprise environments or high-performance computing, and can provide benefits such as increased storage capacity, improved read/write speeds, and protection against data loss. There are several forms of RAID, known as RAID levels, each providing a different balance between performance and redundancy. For example, RAID 0 ('striping') improves performance by distributing data evenly across multiple drives but provides no redundancy, while RAID 1 ('mirroring') creates an exact copy of data on two or more drives to protect against drive failures. Other RAID levels, such as RAID 5 and RAID 10, combine striping and mirroring techniques to offer a balance between performance and data protection.

SCSI is a set of standards for physically connecting and transferring data between computers and peripheral devices. SCSI is most commonly used for hard disk drives and tape drives, but it can connect a wide range of other devices, including scanners and CD drives. SCSI interfaces provide for faster data transfer rates than most other storage technologies. They support Multiple Input/Output devices to be connected simultaneously to a single SCSI interface, allowing for daisy chaining of multiple devices. SCSI is available in several variants, including SCSI-1, SCSI-2, SCSI-3, and SCSI over Fibre Channel and SAS.

Parallel ATA (PATA), also known as Integrated Drive Electronics (IDE) or Enhanced Integrated Drive Electronics (EIDE), is a standard interface for connecting hard drives, CD-ROM drives, and other storage devices to a computer. PATA uses a 40-pin ribbon cable with a 16-bit wide data bus, which allows it to transfer data at a maximum rate of 133 MB/s. Although PATA was popular in the past, it has been replaced by the faster and more advanced Serial ATA (SATA) standard in recent years.

A SAN is a high-speed network of storage devices that is accessible by multiple servers and can be managed centrally. This network provides block-level storage and is often used for mission-critical applications or large-scale data processing tasks. The main advantages of a SAN include improved performance, high availability, and simplified data management. Popular SAN protocols include Fibre Channel, iSCSI, and Fibre Channel over Ethernet (FCoE). A SAN can be composed of various storage devices such as HDDs, SSDs, and RAID systems.

NAS is a storage technology that allows multiple users or devices to access and share files over a network. It is essentially a specialized file server that is optimized for file sharing. NAS is known for its ease of use and simple setup process. It usually comes as a pre-built solution or can be built using NAS software. Regardless of the implementation, NAS entries are made of one or more storage drives, and function as a centralized storage system for all users and devices on the network. It uses standard file protocols such as SMB/CIFS, NFS, and AFP, allowing compatibility with a variety of devices and operating systems.

SD cards are non-volatile flash memory cards that are most commonly used in portable devices like mobile phones, digital cameras, and tablets. These cards store digital data, providing an easy way to expand storage capacity or transfer data between devices. They come in different sizes, including the original SD (up to 2 GB), SD High Capacity (SDHC, up to 32 GB), and SD Extended Capacity (SDXC, up to 2 TB). SD cards can be further classified by their speed class, which indicates the minimum sustained write speed supported by the card. The most recent standard is the Ultra High-Speed (UHS) class, which offers faster data transfer rates for high-resolution photos and videos.