Bits and Bytes both measure amounts of data. However, they are typically used in two different contexts.
Bits, kilobits (Kbps), and megabits (Mbps) are most often used to measure data transfer speeds. This may refer to how fast you are downloading a file, or how fast your Internet connection is. For example, if you are downloading a file on cable modem, your download speed might be 240Kbps. This is much faster than a dial-up modem, which maxes out at 56Kbps.
Bytes, on the other hand, are used to measure data storage. For example, a CD holds 700MB (megabytes) of data and a hard drive may hold 250GB (gigabytes). The other important difference is that bytes contain eight bits of data. Therefore, a 240Kbps download is only transferring 30KB of data per second. However, kilobytes per second is not as commonly used as kilobits per second for measuring data transfer speeds. After all, using kilobits per second (Kbps) makes your connection sound eight times faster!
It is important to know that bytes are abbreviated with a capital B, where as bits use a lowercase b. Therefore, Mbps is megabits per second, and MBps is megabytes per second. So 8Mbps is equal to 1MBps.
Wednesday, September 30, 2009
What does the "NT" stand for in Windows NT?
The NT in Windows NT stands for "New Technology." Windows NT was built with primarily the same interface as Windows 95, but included new technology such as preemptive multitasking and was the first 32-bit version of the Windows operating system. Some argue that because of the new networking options included with Windows NT, the abbreviation stands for "Networking Technology." However the official meaning of NT, according to Microsoft, is "New Technology."
Windows NT was originally developed to be a a reliable and scalable operating system for businesses. However, the NT kernel later became the foundation of Windows 2000 and then Windows XP, which is available in both Home and Professional versions.
Windows NT was originally developed to be a a reliable and scalable operating system for businesses. However, the NT kernel later became the foundation of Windows 2000 and then Windows XP, which is available in both Home and Professional versions.
Can someone hack into my computer if it is not connected to the Internet?
If your computer is not connected to the Internet, there is no way for information to be transmitted to or from the computer over the Internet. If you have a modem connected to a phone line and have your computer set to receive incoming calls, it is theoretically possible for someone to hack into it, but extremely unlikely.
The only way for someone to hack into a computer not connected to the Internet or a phone line it is to physically use the computer. While manufacturers may include chips that uniquely identify your computer, they do not put in chips that transmit any kind of information about your system. Any personal information you have on your computer is stored on your hard drive and is safe as long as no one accesses it. Therefore, it is a good idea to require a password to log in to your computer. It is also wise to erase your hard drive and "zero all data" before selling or giving your computer to someone else.
The only way for someone to hack into a computer not connected to the Internet or a phone line it is to physically use the computer. While manufacturers may include chips that uniquely identify your computer, they do not put in chips that transmit any kind of information about your system. Any personal information you have on your computer is stored on your hard drive and is safe as long as no one accesses it. Therefore, it is a good idea to require a password to log in to your computer. It is also wise to erase your hard drive and "zero all data" before selling or giving your computer to someone else.
Should I turn off my computer or put it to sleep
This question can invoke quite a bit of debate, but my short answer is to put the computer to sleep each night or any time you leave the computer for more than 15 minutes. If you are not going to use the computer for more than a day (such as leaving it for the weekend), it is best to turn the computer off.
Idle 15 minutes to 24 hours: Sleep Idle 24 hours or more: Shut Down
When a computer is in "sleep" or "standby" mode, it consumes almost no energy, so the difference between letting it sleep overnight or turning it off during the night is negligible. However, if you have a laptop running off a battery charge, the difference may be noticeable. I have noticed that my laptop's battery life only lasts about five to six days in sleep mode, but will last for weeks if the computer is off. Therefore, if you are not going to be using your laptop for more than a few hours and do not have AC power available, it is best to turn the computer off.
The most important way to save energy is to not leave the computer running normally when you are not using it. I have my computer set to automatically sleep if it is idle for 15 minutes and my screen dims after 5 minutes. This way, I know that I won't accidentally leave my computer running for a long period of time. I also put my computer to sleep manually if I know I am going to be taking a break for more than 15 minutes.
Finally, if you put your computer to sleep every night and hardly ever turn if off, it may be good to at least restart the computer every few weeks. This may help improve performance in case some errant processes are consuming unnecessary RAM or CPU time.
Windows users: Read more about the differences between Standby and Hibernate modes.
Mac users: The Mac OS X keyboard shortcut for putting your computer to sleep is Command-Option-Eject.
Idle 15 minutes to 24 hours: Sleep Idle 24 hours or more: Shut Down
When a computer is in "sleep" or "standby" mode, it consumes almost no energy, so the difference between letting it sleep overnight or turning it off during the night is negligible. However, if you have a laptop running off a battery charge, the difference may be noticeable. I have noticed that my laptop's battery life only lasts about five to six days in sleep mode, but will last for weeks if the computer is off. Therefore, if you are not going to be using your laptop for more than a few hours and do not have AC power available, it is best to turn the computer off.
The most important way to save energy is to not leave the computer running normally when you are not using it. I have my computer set to automatically sleep if it is idle for 15 minutes and my screen dims after 5 minutes. This way, I know that I won't accidentally leave my computer running for a long period of time. I also put my computer to sleep manually if I know I am going to be taking a break for more than 15 minutes.
Finally, if you put your computer to sleep every night and hardly ever turn if off, it may be good to at least restart the computer every few weeks. This may help improve performance in case some errant processes are consuming unnecessary RAM or CPU time.
Windows users: Read more about the differences between Standby and Hibernate modes.
Mac users: The Mac OS X keyboard shortcut for putting your computer to sleep is Command-Option-Eject.
Can someone spy on my computer?
With all the different types of spyware and malware floating around, it is natural to wonder if other users can see what you are doing on your computer. The good news is that it is very unlikely.
Most modern operating systems, such as Mac OS X and Windows Vista, have a high level of security that prevents unauthorized access. Even if there is a partial breach in your system's security, it is still nearly impossible for another user to spy on your system. For example, a major security hole may give an unknown user access to a directory on your hard drive, but he or she would still not be able to "see" your computer. Also, spyware programs may collect data without your knowledge, but this information is only acquired from the spyware program itself, not the rest of the system.
The most likely way for someone to spy on your system is with a Remote Desktop program. These programs, such as PC Anywhere, Windows Remote Desktop Connection (RDC), and Apple Remote Desktop, allow users to view another computer's screen on their desktop. Of course, the computer being accessed must allow incoming connections for this to happen. This option is typically turned off by default. However, if your computer is part of an office network, you may want to ask the network administrator if your computer has remote access enabled. If so, it may be possible for someone on your local network to view your computer screen.
Fortunately, most remote desktop programs have notifications that alert the user if the computer is being observed by someone else. These notifications may appear in the Task Bar (Windows) or the Menu Bar (Mac). So if you're at work and you see an icon that looks like a pair of eyes or a binoculars appear somewhere on your desktop, someone may in fact be watching your screen. It might be time to close Solitaire and get back to work.
Most modern operating systems, such as Mac OS X and Windows Vista, have a high level of security that prevents unauthorized access. Even if there is a partial breach in your system's security, it is still nearly impossible for another user to spy on your system. For example, a major security hole may give an unknown user access to a directory on your hard drive, but he or she would still not be able to "see" your computer. Also, spyware programs may collect data without your knowledge, but this information is only acquired from the spyware program itself, not the rest of the system.
The most likely way for someone to spy on your system is with a Remote Desktop program. These programs, such as PC Anywhere, Windows Remote Desktop Connection (RDC), and Apple Remote Desktop, allow users to view another computer's screen on their desktop. Of course, the computer being accessed must allow incoming connections for this to happen. This option is typically turned off by default. However, if your computer is part of an office network, you may want to ask the network administrator if your computer has remote access enabled. If so, it may be possible for someone on your local network to view your computer screen.
Fortunately, most remote desktop programs have notifications that alert the user if the computer is being observed by someone else. These notifications may appear in the Task Bar (Windows) or the Menu Bar (Mac). So if you're at work and you see an icon that looks like a pair of eyes or a binoculars appear somewhere on your desktop, someone may in fact be watching your screen. It might be time to close Solitaire and get back to work.
Why polygons are used in 3D graphics
As realistic as 3D graphics may appear, they are typically comprised of flat, multi-sided polygons. These polygons are placed together to create a three-dimensional mesh, which produces a 3D image. While most polygons are triangles (which have the fewest possible sides), they can also be rectangles, hexagons, or other shapes. Colors and textures can be mapped onto these polygons, giving the final image a realistic appearance.
Because polygons are flat surfaces, they can only estimate curved shapes, which many objects have. Therefore, smaller polygons can more accurately represent curved objects. Of course, using smaller polygons also means more polygons are required to create the object. So the more polygons a 3D model has, the more smooth and realistic it will look.
For example, imagine a 3D image of a round ball that is three inches in diameter. If the ball was made up of only 100 polygons, it would be easy to notice the flat surfaces, making the ball seem rather blocky. However, if 1,000 polygons were used, the shapes would be less noticeable, giving the ball a smoother look. If 100,000 polygons were used to create the surface of the ball, the ball might appear completely round. The same concept holds true for more complex models, such as three-dimensional characters and other objects.
Thanks to advances in graphics processing technology, today's video cards can render millions of polygons per second. This allows for several highly detailed 3D models to be displayed on the screen at one time. Therefore, if you want to play a 3D video game on your computer with highly realistic graphics, chances are you'll need a video card with a powerful GPU.
Because polygons are flat surfaces, they can only estimate curved shapes, which many objects have. Therefore, smaller polygons can more accurately represent curved objects. Of course, using smaller polygons also means more polygons are required to create the object. So the more polygons a 3D model has, the more smooth and realistic it will look.
For example, imagine a 3D image of a round ball that is three inches in diameter. If the ball was made up of only 100 polygons, it would be easy to notice the flat surfaces, making the ball seem rather blocky. However, if 1,000 polygons were used, the shapes would be less noticeable, giving the ball a smoother look. If 100,000 polygons were used to create the surface of the ball, the ball might appear completely round. The same concept holds true for more complex models, such as three-dimensional characters and other objects.
Thanks to advances in graphics processing technology, today's video cards can render millions of polygons per second. This allows for several highly detailed 3D models to be displayed on the screen at one time. Therefore, if you want to play a 3D video game on your computer with highly realistic graphics, chances are you'll need a video card with a powerful GPU.
What does a bank refer to in computer terminology ?
Most of us think of banks as places where we can deposit and withdraw money. In the computer world, the term "bank" is a bit more ambiguous. It can mean several different things, but most often it refers to a memory bank. Memory banks are similar to financial banks, except they serve as a data repository rather than a place to store money.
A bank may also refer to a set of memory modules, such as SIMMs or DIMMs. Memory modules are sometimes organized into different groups on a motherboard and each group is called a bank.
Finally, the term "bank" can be loosely used to describe a general storage area for computer data. For example, a person might say he uploaded a backup copy of his document to an online data bank. Once the document is stored in the data bank, the user can retrieve it at a later time.
A bank may also refer to a set of memory modules, such as SIMMs or DIMMs. Memory modules are sometimes organized into different groups on a motherboard and each group is called a bank.
Finally, the term "bank" can be loosely used to describe a general storage area for computer data. For example, a person might say he uploaded a backup copy of his document to an online data bank. Once the document is stored in the data bank, the user can retrieve it at a later time.
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