Welcome to optical drives and external storage. After watching this video, you’ll be able to: Identify how an optical drive records data. Describe an external storage device. Apply knowledge of expansion devices to choose the best one for your needs. Data is written to optical devices through a laser pressing or ‘burning’ the disk. This creates recessed areas (known as pits) and raised areas (known as lands). The laser reads and writes data on the reflective surface of the disk. Single-sided disks have one recordable layer to write data to. Storage capacity is usually 4.7 GB for a DVD ROM and 700 MB for a CD. Double-sided disks have two layers on which to record data. They hold twice as much data as a single-layer disk. There are many types of optical drives. These include: CD-ROM, CD-RW, DVD-ROM, DVD-RW, and Blu-ray, which has a data capacity of 50 gigabytes (50 GB). CD and DVD writers, such as CD-R and DVD-R drives, use a laser to read and write data on the discs. A solid-state drive (SSD) uses integrated circuit assemblies to store data, typically using flash memory and functioning as permanent secondary storage. It is also sometimes called a solid-state device or a solid-state disk even though SSDs lack the physical spinning disks and movable read-write heads used in hard disk drives (HDDs) and floppy disks. An external hard drive is an excellent medium to back up and transfer files. They can store a large amount of data, including documents, spreadsheets, presentations, music, and videos. Most external hard drives connect to a computer through a USB or eSATA connection. Many draw power from the computer's USB port. External SATA or eSATA is a SATA connector accessible from outside the computer, to provide a signal (but not power). If the external hard drive requires a power cord, connect it to the back of the hard drive. The end of the power cord that connects to the hard drive is usually a small round connector. Connect the other end of the power cord to a power outlet. If no power cord is required, skip to the next step. Connect the USB cable to the external hard drive. Plug the other end of the USB cable into a USB port on the computer. After connecting the external hard drive to the computer, it should be recognized automatically by your computer's operating system. Your computer should find and install any necessary drivers. In Windows, File Explorer may automatically open, displaying the contents of the external hard drive. If File Explorer does not automatically open, manually open File Explorer and locate the drive. An expansion drive provides extra storage for an ever-growing collection of files. It typically attaches to the computer with a USB connection. Expansion drives consolidate files into a single location and frees computer space. The drive is automatically recognized by the Windows operating system so there's no software to install or configure. One example of an expansion drive is a USB/thumb drive. These drives have a storage capacity of up to 2 terabytes (2TB). A USB flash drive is an expansion device that includes flash memory with an integrated USB interface. It is typically removable, rewritable, and much smaller than an optical disc. Most weigh less than 1 oz. Since first appearing on the market in late 2000, as with virtually all other computer memory devices, storage capacities have risen while prices have dropped. As of 2018, 2 TB flash drives were the largest available in terms of storage capacity. Some are thought to last between 10 and 100 years under normal circumstances (shelf storage time). A memory card is used to store digital information, typically using flash memory. These are commonly used in portable devices such as digital cameras, cell phones, laptop computers, and portable media players. The card is stored inside a device; this differs it from USB drives. Memory cards are available in both Secure Digital (SD) and Micro Secure Digital (MSD) formats. Common data capacities are 32 GB, 64 GB, and 128 GB. Some of the latest generation memory cards offer 512 GB memory card capacities. Portable media players and smartphones are other types of storage devices. A portable media player is any type of electronic device that is capable of handling digital media. Depending on the device, the types of media files that can be played include digital music, audiobooks, and video. A mobile media player is often part of a smartphone. It is important to understand the difference between internal and external (or expandable) memory. Internal memory is the manufacturer-installed storage space, usually, 16, 32, or 64GB, where the operating system, pre-installed apps, and other system software are installed. The total amount of internal storage cannot be increased or decreased by the user, so if your phone has only 16GB of internal storage and no expansion slot, this is all the storage space you will ever have. And remember, some of this will already be used up by the system software. External, or expandable, memory refers to a removable microSD card or similar format. But not all phones will have this extra storage capability included. If storage, for music, images, or other user-added files, is important to you, the ability to add another 32GB or even 64GB card should be an important consideration. In this video you learned that: Optical drives record data using a laser on a reflective disk. An external storage device such as an external hard drive often connects to a computer via a universal series bus (USB) connection. External hard drives and USB drives are solid-state, which means they’ve got no moving parts. They’re faster and more expensive than traditional hard drives. The best storage option for you will depend on your needs and your budget. Smartphones and media players offer portable storage as well as extensive functionality. Solid State Drive (SSD) media such as external hard drives, USB drives, and memory cards increase the storage capacity of a system.