Hardware Flashcards
Hard drive
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that uses magnetic storage to store and retrieve digital information using one or more rigid rapidly rotating disks (platters) coated with magnetic material. The platters are paired with magnetic heads, usually arranged on a moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a random-access manner, meaning that individual blocks of data can be stored or retrieved in any order and not only sequentially. HDDs are a type of non-volatile storage, retaining stored data even when powered off.
Solid State Drive (SSD)
Stands for “Solid State Drive.” An SSD is a type of mass storage device similar to a hard disk drive (HDD). It supports reading and writing data and maintains stored data in a permanent state even without power. Internal SSDs connect to a computer like a hard drive, using standard IDE or SATA connections. While SSDs serve the same function as hard drives, their internal components are much different. Unlike hard drives, SSDs do not have any moving parts (which is why they are called solid state drives). Instead of storing data on magnetic platters, SSDs store data using flash memory. Since SSDs have no moving parts, they don’t have to “spin up” while in a sleep state and they don’t need to move a drive head to different parts of the drive to access data. Therefore, SSDs can access data faster than HDDs. SSDs have several other advantages over hard drives as well. For example, the read performance of a hard drive declines when data gets fragmented, or split up into multiple locations on the disk. The read performance of an SSD does not diminish based on where data is stored on the drive. Therefore defragmenting an SSD is not necessary. Since SSDs do not store data magnetically, they are not susceptible to data loss due to strong magnetic fields in close proximity to the drive. Additionally, since SSDs have no moving parts, there is far less chance of a mechanical breakdown. SSDs are also lighter, quieter, and use less power than hard drives. This is why SSDs have become a popular choice for laptop computers. While SSDs have many advantages over HDDs, they also have some drawbacks. Since the SSD technology is much newer than traditional hard drive technology, the price of SSDs is substantially higher. As of early 2011, SSDs cost about 10 times as much per gigabyte as a hard drive. Therefore, most SSD drives sold today have much smaller capacities than comparable hard drives. They also have a limited number or write cycles, which may cause their performance to degrade over time. Fortunately, newer SSDs have improved reliability and should last several years before any reduction in performance is noticeable. As the SSD technology improves and the prices continue to fall, it is likely that solid state drives will begin to replace hard disk drives for most purposes.
Random-access Memory (RAM)
RAM (Random Access Memory) is the hardware in a computing device where the operating system (OS), application programs and data in current use are kept so they can be quickly reached by the device’s processor. RAM is the main memory in a computer. It is much faster to read from and write to than other kinds of storage, such as a hard disk drive (HDD), solid-state drive (SSD) or optical drive. Random Access Memory is volatile. That means data is retained in RAM as long as the computer is on, but it is lost when the computer is turned off. When the computer is rebooted, the OS and other files are reloaded into RAM, usually from an HDD or SSD. Because of its volatility, RAM can’t store permanent data. Short-term memory is focused on immediate work, but it can only keep a limited number of facts in view at any one time. When a person’s short-term memory fills up, it can be refreshed with facts stored in the brain’s long-term memory. A computer also works this way. If RAM fills up, the computer’s processor must repeatedly go to the hard disk to overlay the old data in RAM with new data. This process slows the computer’s operation. To understand RAM, let’s use the analogy of a physical desk. Your working space is the top of the desk. That’s where you keep everything you frequently use within arm’s reach, so you won’t waste time searching through your drawers. By contrast, anything you don’t use that much or that you want to save for later goes into a desk drawer. The RAM chip may be individually mounted on the motherboard or in sets of several chips on a small board connected to the motherboard. Older memory types were in the form of chips called dual in-line package (DIP). Although DIP chips are still used today, the majority of memory is in the form of a module, a narrow printed circuit board attached to a connector on the motherboard. The three main memory circuit boards types containing chips are: RIMMs (Rambus in-line memory modules), DIMMs (dual in-line memory modules) and SIMMs (single in-line memory modules). Most motherboards today use DIMMs.
Optical Drive
An optical drive is a type of computer disk drive that reads and writes data from optical disks through laser beaming technology.
This type of drive allows a user to retrieve, edit and delete the content from optical disks such as CDs, DVDs and Blu-ray disks. Optical drives are among the most common computer components. An optical drive may also be known as an optical disk drive (ODD). Most drives also allow you to write data to a disc, so you can create your own music CDs, video DVDs or even create of back-up copy of your important data files. In computing, an optical disc drive is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only read from certain discs, but recent drives can both read and record, also called burners or writers.
Motherboard
A motherboard (sometimes alternatively known as the mainboard), is the main printed circuit board (PCB) found in general purpose computers and other expandable systems. It holds, and allows, communication between many of the crucial electronic components of a system, such as the central processing unit (CPU) and memory, and provides connectors for other peripherals. A motherboard usually contains significant sub-systems such as the central processor, the chipset’s input/output and memory controllers, interface connectors, and other components integrated for general purpose use and applications.
PC case
A computer case safeguards all of the important—and expensive—parts of a PC or other computing device. Internal components include things like the motherboard, chassis, drives, CPU and more for small desktop units, all the way through whole networks and even up to advanced blade servers.
Power Supply
A power supply unit (PSU) converts mains AC to low-voltage regulated DC power for the internal components of a computer. Modern personal computers universally use switched-mode power supplies. Some power supplies have a manual switch for selecting input voltage, while others automatically adapt to the mains voltage. The desktop computer power supply converts the alternating current (AC) from a wall socket of mains electricity to a low-voltage direct current (DC) to operate the motherboard, processor and peripheral devices. Several direct-current voltages are required, and they must be regulated with some accuracy to provide stable operation of the computer. A power supply rail or voltage rail refers to a single voltage provided by a PSU.
Speakers
Speakers are one of the most common output devices used with computer systems. Some speakers are designed to work specifically with computers, while others can be hooked up to any type of sound system. Regardless of their design, the purpose of speakers is to produce audio output that can be heard by the listener.
Keyboard and Mouse
Along with the mouse, the keyboard is one of the primary input devices used with a computer. The keyboard’s design comes from the original typewriter keyboards, which arranged letters and numbers in a way that prevented the type-bars from getting jammed when typing quickly. This keyboard layout is known as the QWERTY design.
A computer mouse is an input device that is used with a computer. Moving a mouse along a flat surface can move the cursor to different items on the screen. Items can be moved or selected by pressing the mouse buttons Today’s mice have two buttons, the left button and right button, with a scroll wheel in between the two. Today, many computer mice use wireless technology and have no wire. There are many types of mouse. Optical mouse, wireless mouse, mechanical mouse, trackball mouse. A computer mouse is a handheld hardware input device that controls a cursor in a GUI and can move and select text, icons, files, and folders. The mouse was originally known as the X-Y position Indicator for a display system and was invented by Douglas Engelbart in 1963 while working at Xerox PARC. However, due to Alto’s lack of success, the first widely used application of the mouse was with the Apple Lisa computer.
Router
A router[a] is a networking device that forwards data packets between computer networks. Routers perform the traffic directing functions on the Internet. Data sent through the internet, such as a web page or email, is in the form of data packets. A packet is typically forwarded from one router to another router through the networks that constitute an internetwork (e.g. the Internet) until it reaches its destination node.
A router is connected to two or more data lines from different IP networks.[b] When a data packet comes in on one of the lines, the router reads the network address information in the packet header to determine the ultimate destination. Then, using information in its routing table or routing policy, it directs the packet to the next network on its journey.
The most familiar type of IP routers are home and small office routers that simply forward IP packets between the home computers and the Internet. More sophisticated routers, such as enterprise routers, connect large business or ISP networks up to the powerful core routers that forward data at high speed along the optical fibre lines of the Internet backbone.
Network Interface Card (NIC)
Short for network interface card, the NIC is also referred to as an Ethernet card and network adapter. A NIC is a computer expansion card for connecting to a network (e.g., home network or Internet) using an Ethernet cable with an RJ-45 connector. Due to the popularity and low cost of the Ethernet standard, nearly all new computers have a network interface build directly into the motherboard. Network cards can communicate with each other over the same network using a network switch, or if two computers are directly connected. When computers need to connect to a different network (e.g., the Internet), they must be use a router to route the network packets to the correct network. Operating as an interface, a NIC card can transmit signals at the physical layer and deliver data packets at the network layer. Irrespective of location, the NIC card acts as a middleman between a computer, or server, and a data network. When a user requests a web page, the LAN card gets data from the user device, sends it to the server via the Internet, and gets the required data back from the Internet to display for users.
USB
A USB flash drive is a device used for data storage that includes a flash memory and an integrated Universal Serial Bus (USB) interface. Most USB flash drives are removable and rewritable. Physically, they are small, durable and reliable. The larger their storage space, the faster they tend to operate. USB flash drives are mechanically very robust because there are no moving parts. They derive the power to operate from the device to which they are connected (typically a computer) via the USB port.
