How does CPU work?
The central processing unit of a computer processes instructions, performs calculations and manages the flow of information through a system. It turns raw data into information through the use of its two parts: the control unit and the arithmatic logic unit (ALU). As the names suggest, the control unit coordinates all the other components and the ALU does all of the arithmatic (addition, subtraction, multiplication and division), and makes all the logic and comparison decisions. The steps involved in a CPU's function are to fetch data from RAM, decode it into language that the CPU can understand, execute the instructions given by the data and store the results to RAM before restarting the pattern. This system of steps is called a machine cycle.
How does a hard disk work?
A hard disk or hard drive is made of a pile of round, thin plates of metal called platters. To save data, magnetized spots are created on the coating representing binary digits and therefore information. The coating on the disks allow them to be written on both sides, adding to the amount of data that can be stored. The coatings are written in a process called low-level formatting, inscribing concentric circles called tracks and pie-shaped wedges called sectors. This helps the computer to organize the files . High-level formatting creates the table that helps the computer to keep track of which files are stored where. The platters spin very quickly and special "arms" called read-write heads move across directly above them like the arm of a record-player.
How can I determine whether I should upgrade my computer or buy a new one?
After determining what you need from a computer and deciding that your computer does not meet those standards, you must figure out how much it would cost to buy a new system with the needed components and how much it would cost to upgrade the current system to what is needed. In some cases a computer with the needed specifications may not exist, and may have to be custom-built, significantly adding to the price. Upgrades to the CPU, operating system, RAM, hard drive, solid state drive, CD, DVD, or blu-ray burner, video card and sound card can be considered.
How can I improve the reliability of my system?
If your system often crashes, check that you have enough RAM, make sure new software or hardware is properly installed or try "rolling back" to a previous restore point using the System Restore utility in Windows or Time Machine in Mac. Tto improve reliability you can also upgrade to the latest software products. Often software patches and upgrades fix "bugs". You can also use the problem steps recorder to capture the exact steps of the problem in order to learn more about it, or try reinstalling or upgrading the operating system.
What is access time? What is clock speed?
Access time is how long it takes a storage device to locate its stored data and make it available for processing. It is usually measured in milliseconds. It is mostly composed of two factors: seek time and latency. Seek time is how long it takes for the read/write heads to move over the surface of the disk. Latency is the time the read/write head has to wait for the right part of the platter to spin into the correct place. The faster the spin, the shorter these two periods will be. Clock speed is how many instructions the CPU can finish processing in one second.
f. What is data transfer rate?
Data transfer rate is the maximum speed at which data can be transmitted between two nodes on a network. It is usually measured in megabits per sonced (Mbps).
What is read/write head?
The read/write head is the end of an "arm" in the hard drive that moves across a platter like the arm of a record player but much faster. It retrieves and records the magnetic data stored on the platter.
What is a computer network? What are the benefits of a computer network?
A computer network is two or more computers that are connected via software and hardware so they can communicate with each other. The benefits of a computer network include sharing resources like internet connections and peripheral devices like printers. It also helps to share files easily and wirelessly between computers.
Compare peer-to-peer networks and client/server networks
A peer-to-peer (P2P) network is one where all computers are equal, and can perform their own tasks. They are common for small setups. Larger setups usually use a client/server network, where there are two types of computers. Client computers are the ones that are actually used for specific tasks, like writing papers and printing. The server computer provides resources to the client computers, and is the administrator of the network. Often, the client computers send a request to print a file to the server computers, and the servers actually signal the printing. Internet service providers are an example of a client/server network. They are the server, turning a basic computer into a client while surfing the internet.
What does HAN stand for? LAN? WAN? MAN?
- HAN means home area network. LAN means local area network
- WAN means wide area network
- MAN means metropolitan area network
List three network components.
1. A means of connecting the nodes on the network (cables or wireless), such as radio waves for wireless and twisted-pair cable, coaxial cable or fiber-optic cable for wired. This is called transmission media. 2. Special devices that allow nodes to communicate with each other and send data, such as a network interface card. These are called network adapters. 3. Software that allows the network to run, such as an operating system that supports P2P networking or a special network operating system (NOS) for a client/server network.
What is wireless access point?
A wireless access point allows wireless devices to connect to a wired network using Wi-Fi. It usually connects via a router (or is a router).
What is bandwidth?
Bandwidth, aka data transfer rate, is the maximum speed at which data can be transmitted between two nodes on a network. It is usually measured in megabits per second (Mbps).
What is Wi-Fi?
Wi-Fi stands for wireless fidelity. It is a standard for wireless transmissions using radio waves and is used to connect computers to wireless networks or the internet.
What is firewall? What is firmware?
A firewall is a software program or hardware device designed to prevent unauthorized access to computers or networks. Firmware is system software that controls hardware devices.
What are the advantages of a digital format?
Digital formats turn pictures and sounds into a long string of numbers, which makes it much simpler to reproduce the exact sound and light wave the same way every time. It is also easier to distribute, like in streaming or attaching to an email or Facebook message and sending over the internet.
What is cell/smartphone synchronization?
Cell/smartphone synchronization is the process of updating data so that the files on the cell/smartphone and those on the computer are the same. This allows you to keep things like to-do lists updated.
Briefly explain 3G and 4G.
3G and 4G are standards of fast data transfer. 3G is available almost everywhere, not requiring a hotspot to use, and speeds up mobile transfer rates between 0.6 and 2.3 Mbps. 4G is the newer incarnation, available in fewer places, but capable of speeds up to 100 Mbps. Most service providers are not yet capable of providing 4G.
What is voice over Internet protocol?
Voice over Internet Protocol is a technology that facilitates making telephone calls across the internet instead of using conventional telephone lines.
How do cell/smartphone components resemble a traditional computer, and how do they work?
A cell/smartphone, like a regular computer, has a central processor, memory and an operating system. These components work the same way in a computer as they do in a smartphone to process information and support communications, software applications and other services.
What change does ubiquitous computing bring to our lifestyles?
The inclusion of computer devices in our everyday lifestyle is referred to as ubiquitous computing. As computers become smaller it becomes increasingly easier to include them in our everyday life. Most automobile keys now come with an embedded computer inside. I have seen kitchen appliances and even clothing that uses computing technology. Mostly this is useful in streamlining; devices are being created that can do multiple jobs and defeat the need for so many devices.
What are computer viruses? List their types.
- Computer viruses are programs that attach themselves to other computer programs and attempts to spread when files are exchanged. Their classifications are polymorphic, multipartite and stealth.
- Boot-Sector Viruses
- Logic Bombs and Time Bombs
- Worms (some argue that these are not viruses because of their reproduction technique)
- Script viruses
- Macro viruses
- Email viruses
- Encryption viruses
Who are hackers? List their types.
- A hacker is someone who breaks into computer systems to create mischief or steal valuable information.
- White-hat hackers
- Black-hat hackers
- Grey-hat hackers
What does DoS stand for? DDoS?
- DoS stands for denial-of-service attack, which happens when a hacker is tying up the resources of a network and deny legitimate users access.
- DDos is distributed denial of service attack, which is an automated attack launched from more than one zombie (hacker-controlled) computer at the same time.
What is Bluesnarfing? Bluebugging?
Bluesnarfing is unauthorized access of information from a wireless device through a Bluetooth connection. Bluebugging is a technique not unlike phone-eavesdropping (“bugging”), but done by hackers on bluetooth devices, accessing mobile commands covertly and listening in to phone calls. It is very much like bluesnarfing but a bluebugger must be closer to the target.
Compare adware and spyware.
Adware is a program that downloads on your computer when you install a freeware program. It enables sponsored advertisements to appear in the browser or as a pop-up. Spyware is an unwanted piggyback program that also downloads with software but then runs in the background of your system.
Compare SPAM and SPIM.
SPAM is unwanted junk email. SPIM are unwanted instant messages.
What are cookies in computer term?
A cookie is a small text file that some Web sites automatically store on a client computer’s hard drive when the client visits the site.
What is phishing and what is pharming?
- Phishing is the process of sending email messages to lure Internet users into revealing personal information that could lead to identity theft.
- Pharming is planting malicious code on a computer that alters the ability of the browser to find web addresses and sends the user to bogus web sites.
What can I do to protect my computer from viruses?
Short of never interacting with any other computers or networks, up-to-date antivirus software is the best defense against viruses. Complete virus checks should be run at least once a week.
How do I create secure passwords and manage all of my passwords?
Secure passwords contain a mixture of upper and lower case letters, numbers and symbols and are at least 14 characters long. They should not contain easy-to-guess information, like your birthday or your pet’s name. Online password checkers can evaluate the strength of your password. Web browsers and internet security software contain features that manage passwords for you, preventing you from having to memorize multiple complex passwords.
What is a Trojan horse and what is a worm?
A Trojan horse is a computer program that appears to be something useful but does something malicious in the background without the user’s knowledge. A worm is a program that attempts to travel between systems through network connections to spread infection. They can run independently of host file execution and are active in spreading themselves.