Router and Switch

Difference between router and switch

In those early days when router is router and switch is switch, these two are different in several ways:

 ·     Router understand IP head, and switch deal with MAC address

 ·     Router has its own IP address, and switch don’t

 ·     Router has an operating system running inside, and allow administrator to login into the system.

 ·     Network Administrator must configure routing table to make it works.

 ·     Switch is usually ready to use.

 ·     Router has routing software running inside, including route discovery protocol.
 ·     Routing software know how to deal with different IP packet, such as ICMP and other IP option functionality. Switches don’t.

 ·     Multiple routers can be connected together as a network.

 ·     You can’t directly multiple switches together to form a large network.

Mash up

Mashup comes from the term "Mashed Potato". Mashup combines services from different website into a single website. It provides service of combining different or the best of two online software into a single software. Mashups are most commonly a combination of maps and search locator services. One of the most popular mashup includes Google Transit.

NSFNET

NSFNET was a network for research computing deployed in the mid-1980s that in time also became the first backbone infrastructure for the commercial public Internet. Created as a result of a 1985 National Science Foundation (NSF) initiative, NSFNET established a high-speed connection among the five NSF supercomputer centers and the National Center for Atmospheric Research, and provided external access for scientists, researchers, and engineers who were not located near the computing centers.

By the early 1990s, as commercial networks began to build their own backbone infrastructures and their own routing mechanisms, the public service furnished by NSFNET's backbone was turned over to the newer backbones and NSFNET was shut down. The scientific and research network continued as vBNS and, more recently, Internet2.

Hibernate vs Sleep

Sleep is commonly known as Standby in Windows system. In Sleep mode, the power supply to non-essential and non-critical component is withheld, and most system operation is shutdown and stopped. In Sleep mode, the power load reduce considerably, saving a lot of energy. However, the power must not be cut off, and must be continue to supply to the computer. Once out of power, the system will have to start again just like a newly boot computer just started from power off state.

On the other hand, Hibernate will save the data in physical memory to hard disk drive (HDD), and then power off the computer. When user wants to use the computer again, the computer will boot up and load back the state at the last hibernation. The advantage of Hibernation mode is that no power is wasted for maximum saving of power. In Hibernation dormancy, no electricity is consumed by system. Beside, restore from Hibernate is generally faster than computer reboot, and is totally different from fresh start, as users can return to the exact state of last hibernation with all programs running and documents opened intact, instead of empty desktop.

Active-Matrix VS Passive-Matrix Display

Passive-Matrix LCDs were standard in most early laptops (although a few used plasma displays) and the original Nintendo Game Boy until the mid-1990s, when color active-matrix became standard on all laptops. Passive-matrix LCDs are still used today for applications less demanding than laptops and TVs. In particular, these are used on portable devices where less information content needs to be displayed, lowest power consumption (no backlight) and low cost are desired, and/or readability in direct sunlight is needed.

Active-Matrix LCDs  is a type of flat panel display, currently the overwhelming choice of notebook computer manufacturers, due to low weight, very good image quality, wide color and response time. Whereas a passive-matrix display uses a simple conductive grid to deliver current to the liquid crystals in the target area, an active-matrix display uses a grid of transistors and capacitors with the ability to hold a charge for a limited period of time.

                                                                Passive-Matrix Display

                                         

                                                                  Active-Matrix Display

World Book Day ! Roses~

Today, there's an event going on in my college..

It is the 23rd of April, They named it "The World Book Days"


From what I heard, UNESCO declared 23rd of April the World Book Days.
This symbolic date for universal literature also marks the passing away of Miguel de Carvantes and William Shakespeare on the same day in 1616.


In the Spanish region of Catalonia, on 23rd of April, a rose is exchanged for each book received.

Mouse OpeRation 3ple Clicking

Double clicking refers to clicking (and, naturally, releasing) a button (often the primary one) twice. Software recognizes both clicks, and if the second occurs within a short time, the action is recognized as a double click.
If the second click is made after the time expires it is considered to be a new, single click. Most modern operating systems and mice drivers allow a user to change the speed of a double click, along with an easy way to test the setting. Some software recognize three or more clicks (triple click), such as progressively selecting a word, sentence, or paragraph in a word processor text page as more clicks are given in a sequence.

Triple clicking in Safari highlights the whole line, including the line break at the end. Firefox stops short of the line break.