STORAGE DEVICES

The video begins by defining storage devices as essential components that hold data, instructions, and information for future use. It outlines common examples of data stored by individuals and businesses, emphasizing the universal need for storage. It then introduces various storage devices like hard disks, external hard disks, NAS, optical disks, and microfilm, distinguishing between primary storage (RAM) and secondary storage, which includes most common devices.

This part explains storage capacity as the amount of bytes a medium can hold and how storage devices record and retrieve data. It clarifies that writing data creates output, and reading data functions as input, though these are categorized as storage devices. The speed of storage devices is discussed, focusing on access time, which is significantly slower for secondary storage compared to primary memory. The video then delves into hard disks, detailing their structure with platters, read/write heads, cylinders, tracks, and sectors, and how data is stored magnetically.

This section elaborates on the characteristics of hard disks, including platters, read/write heads, cylinders, sectors, tracks, revolutions per minute, transfer rate, and access time. It visualizes how data is organized on a hard disk and explains the continuous rotation of platters. The importance of RAID (Redundant Array of Independent Disks) for data availability and Network Attached Storage (NAS) devices for shared network storage is introduced. It also covers external and removable hard disks, their advantages (portability, backup, added storage), and miniature hard disks for smaller devices.

The video explains the role of hard disk controllers, which manage data transfer between the disk and the system bus. It mentions that controllers can be part of the hard disk, motherboard, or a separate adapter card, and highlights various interface types like SATA, EIDE, SCSI, and SSD. Despite manufacturers guaranteeing a lifespan of 3-5 years for hard disks, proper care and preventive maintenance, such as defragmenting and scanning for errors, can extend their life.

This segment introduces flash memory as a non-volatile, solid-state storage technology known for its durability and shock resistance due to having no moving parts. It focuses on Solid State Drives (SSDs), which use flash memory and are becoming increasingly popular for their speed, lower heat generation, less power consumption, and significantly longer lifespan (up to 50 years according to manufacturers) compared to traditional hard disks. It also mentions flash drive applications like USB flash drives and memory cards found in mobile devices and cameras.

The video shifts to cloud storage, an Internet-based service that offers non-physical storage accessible from any device with Internet access. It discusses various cloud storage services (e.g., Google Drive, Skydrive, Dropbox) and their benefits, such as accessibility, sharing, and off-site backup. Subsequently, it introduces optical discs (CDs, DVDs, Blu-rays) as portable storage media made of metal, plastic, and lacquer, primarily used for software, digital photos, movies, and music. It explains the concepts of 'burning' data onto discs and 'ripping' data from purchased discs.

This part details different types of optical discs: CD-ROM (read-only), CD-R (write once), and CD-RW (rewritable). It also covers DVD-ROMs, which offer higher storage capacity than CDs, and notes that most DVD drives are backward compatible. Other specialized storage media discussed include magnetic tape (used for music and data archiving), magnetic stripe cards (credit cards, bank cards with data on a stripe), smart cards (with embedded microprocessors), and microfilm/microfiche (for storing microscopic images of documents).

The final section focuses on enterprise storage, which refers to large-scale storage solutions used by big businesses with numerous employees and vast amounts of data. These systems are designed for heavy use, maximum availability, and efficiency, often involving dedicated servers and networks to provide storage to other servers and connected users. Examples of companies utilizing such storage include PLDT Globe.