What is IP addressing

        Abbreviation of Internet Protocol is IP.

       An IP address is an identifier for a device ( a computer, a printer ... etc) on a TCP/IP network. TCP/IP (Transmission Control Protocol/Internet Protocol) is the protocol used in the internet. Protocol is a  standard set of regulations and requirements which allows two electronic devices to communicate with each other.The TCP/IP  interconnects the network devices on the internet.

       Nowadays two internet protocols are used.

• Internet protocol version 4 [ IPv4 ]
• Internet protocol version 6 [ IPv6 ]         

      IPv4

        This is the currently using protocol for communication. IPv4 uses 32 bit addresses.So that we can have about 4.3 billion unique addresses.

Ex:
      128.92.32.9
      128.96.10.148

       Normally IP addresses are displayed in human readable notation; in decimal format.But IP addresses are binary numbers. As you can see in the example, each octet(8 bits) is separated by a dot. The value of each octet is used to represent the IP address in decimal format as follows.

= 128.92.32.9

   = 128.96.10.148
   

     IPv6

        It is used 128 bit address for IPv6 addressing. So, logically we can have 2¹²⁸, different addresses or approximately  3.4×10³⁸ addresses by using IPv6. It is very large number when comparing with IPv4 address space (more than 7.9×10²⁸ times).

What are popular Linux distributions ?

      Today I'm going talk  some more about Linux operating system than the previous post (Popular operating systems).        

     
 A Linux distribution is a family member of Unix-like family. It is based on Linux kernel. Currently there are more than 600 Linux distributions. Most of the kernel and supporting packages of Linux distributions are free and open source software.

These are some popular distributions:

   
    

• Fedora
• Redhat
• Gentoo
• Novell
• Mandriva
• Ubuntu  
• Debian        

These distributions may be,

1. Commercial or non-commercial
2. Designed for enterprise users or for home users
3. Supported on many types of hardware
4. Built for

• security
• usability 
• portability.

           Any user with a sufficient knowledge can customize a distribution for the need.

Little things about programming languages..........

        What is a programming language

             A programming language is a language to communicate with a computer or a machine.It can be use to create programs to control the behavior of a computer as we need. Programming languages are different from natural languages. Natural languages are used to communicate among people, but programming languages are used to communicate with computers.

      

   There are some basic things that every language have got in common.

Input      

     Take data from a keyboard or a file or some other device.

 Output

      Display data on the screen. Else send data to a file or to another device.

 Arithmetic
      Perform basic arithmetic operations.

Repetition
       Check some conditions and execute the appropriate sequence of statements under the                               conditions.

 Conditional execution

       Repeatedly perform some actions.

   There are thousands of programming languages. Some of the most popular languages are,

      

• Java
• C
• Objective-C
• C++
• C#
• (Visual) Basic
• PHP
• Python
• Perl
• Ruby
• JavaScript

     In the past there were 3 language generations.

First generation

     These are the machine languages. It consists 1s and 0s only. So it is highly efficient and have the ability to  control the machine directly. But the programs were very hard to write and debug because it uses 1s and 0s.

                  But sometimes this first generation languages are used in 

• Kernels 
• Device drivers.

Second generation

                  These are called as assembly languages. These languages had the ability to add some numbers to get the total. The written programs can not use in another computer which means they were used for a specific machine and a microprocessor.

Third generation   

            These are called High level languages. Introduced in late 1950s. These languages are hardware independent. Programs have to be compiled (using a compiler or an interpreter). 

• FORTRAN
• COBOL
• ALGOL    are the early 3GL languages.

        Modern languages like,

• Java
• Ada
• Pascal 
• C, C++, C#   are also 3GL languages. 

                 These 3GL languages are easy to use because the codes are close to the natural language.

New generations are shown below.

Fourth generation
          These are the current modern languages. They are very close (similar) to human languages. 

Fifth generation
           These are the future programming languages. Used for write programs for artificial intelligence.

 

laptop battery life (15 tips)....

           Nowadays Lithium-Ion batteries are used in laptops. The performance of a battery decreases with time, have to replace within 1-3 years.

     So there are some tips to increase your performance of the battery. Easy to follow.

• If possible always plug the battery.         

               You can charge your battery only about 1500 times. After that it will be a dead battery. In new laptops when the battery is fully charged, it works using the normal current. There's no use of the battery at that time if plugged.

    But be careful:

          Normally there are 6 or 9 cells in a battery. From these, the last cells work when the battery is on it's last battery readings (ex: 9%, 15%, 20%). To make them usable, you have to use the battery until it lost its charge(ex: 7% with warning message). You should do this once in 10-12 days.

• Clean the battery contacts

Use a cloth moistened with alcohol.Do it once every 2-3 months.  

• Sleep the laptop if you go away for 2-3 hours.

• Hibernate it if you go away for 10-12 hours. (But always don't do this)

• Restart  the laptop once a week.

• Don't shut down the laptop as a hobby(always don't shut down). 

• Don't put it on standby position always. It will absorb a lot of  battery power to keep ready to go when you open the cover. (So hibernate it)

• Dim your screen to the lowest level as you can.

• Exercise the battery

               When fully charged use it at least once every 2 weeks.

• Remove CD/DVD s ,USB drives.

              When you don't have the power supply by normal current, when you are running on battery do not use CD/DVD. Remove them, if you are not using.Because the power consumption is very high even without use of it.                 

• Keep the laptop cool....

                 For that make sure that your cooling fan is working correctly.

•  Disable Bluetooth.
• Turn down the volume level or mute it when you are not using it.

• If you are not using the web browser ,then close it.
       It runs in the background to get information even if you are not using it.
• Once every 3 months fully discharge your battery.
  
        Use the battery power to run the laptop. Do not plug it. Then the laptop will hibernate.Then keep it about 5 hrs or more.So the battery will fully discharge.
          Then plug it until the battery get fully charged and use it as you wish.......

Brief Introduction to popular operating systems.....

            I'm going to give you a short introduction about the popular operating systems that I mentioned in a previous post (Something about Operating systems).
       
         First let's have a look at the most popular operating system in the world.

    Microsoft Windows

         Microsoft windows operating systems are developed and sold by Microsoft. Windows is a graphical use interface operating system. 

          

     First Microsoft Windows operating system was named as Windows 1.0 and it  was released on 20 th of November,1985. Then it overtook the prsonal computer market from Mac OS.

Families of windows:
         
   Family                       Kernel type
Windows 9x                    DOS
Windows CE                   DOS
Windows NT                   Hybrid

Some versions of Microsoft Windows:

 Windows 2.0                in 1987    
Windows 3.0                in 1990     
Windows NT 3.1          in 1993     
Windows 95                 in 1995     
Windows NT 4.0          in 1996     
Windows 98                 in 1998     
Windows 2000             in 2000     
Windows XP                in 2001     
Windows Vista             in 2006/07
Windows 07                 in 2009     
The latest version Windows 08 will be release soon.
   
 Net market share of Microsoft Windows is shown below(in 2012).

                      

                   Windows 07          40.5%
               Windows Vista      44.9%
               Windows XP           6.9%
               Windows 2000        0.1%
               Windows 98            0.1%

         These operating systems are programmed in C, C++ and  assembly language.Supported platforms are ARM, IA-32, Itanium, x86-64. 

       

         Windows operating systems can be update using Windows Update or Windows Anytime Upgrade.

Linux

      Linux Kernel is the defining component of Linux. Linux was programmed using a lot of languages. The first operating system kernel was released by Linus Torvalds in 5th of October in 1991.

     

Linux is a free operating system. It's a leading operating system on:

• Servers
• Mainframe computers
• Super computers.

   About 90% of 500 fastest super computers run on Linux.It includes the fastest 10 also.

      And in embedded systems such as

• Mobile phones
• Tablet computers
• Network routers
• Televisions                can be run on Linux kernel.             

    

These are some of the Linux kernel  based distributions:

• Fedora
• Ubuntu
• Novell
• Mandriva Linux
• Debian
• Gentoo
• Slackware     

(for more details see Popular Linux distributions)

   

Some of the Linux supported platforms are:

1. Alpha 
2. Hexagon
3. ARM
4. Xtensa
5. MIPS
6. Itanium
7. PowerPC

     

 Some magor co-operations that contribute Linux:

• Dell
• IBM
• HP
• Oracle
• Sun Micro Systems
• Novell
• Nokia

   Most of Linux distributions supported for a lot of programming languages. Some of them are shown here.

          

1.  Java
2. C / C++ / C#
3. PHP
4. Fortran
5. Perl
6. Ruby
7. Python    

Something about Operating Systems...

                                                                            

           An operating system (OS) is a set of software that manages computer hardware. Definition of an OS is the set of software that controls the overall operation of a computer system, typically by performing such tasks as memory allocation, job scheduling and input & output devices.Without an operating system, a computer is useless.
          
         Operating System is a vital component of the system software in a computer system. The operating system act as an intermediary between program and computer hardware. The first computers didn't have an operating system.


Operating systems can be classified as follows:

• Multi-user 

           Allows 2 or more(can be thousands) users to run programs at the same time. 

• Multiprocessing

           Supports running a program  on more than one CPU.

• Multitasking 

            Allows more than one program to run concurrently.

• Multithreading

          Allows different parts of a single program to run concurrently.

• Real time

           Responds to input instantly.

  Popular operating systems 

1. Linux (Ubuntu, RedHat, Fedora, Dabian, DSL... and many more)
2. Windows OS ( XP, Vista, Windows 7 ...etc)
3. Mac OS
4. Unix
5. Sun Solaris OS

OS platform Statics in 2012

                        

                  Windows                  83.6%

                  Mac OS                      9.0% 

                  Linux                          4.9%

                  Mobile                        1.6%

User interfaces of popular operating systems

Ubuntu(Linux)

              

                   Windows

                                                                     

 Android(Linux; for mobiles) 

                                                                  

What are web browsers?

   

                   
         Web browser is a program used to view HTML documents. In other words it is a software application for retrieving, presenting and passing through information resources (web pages, images, videos, discussions....etc ).

         The web browser contact the web server and request information and then the server send information to the web browser. Then the web browser shows the results on the computer screen. So the web browser act as a client between the server and the computer.

 
               As an example the web browser is like a worker in a fuel station. We go an ask for fuel (information) from him (web browser). Then he goes to the fuel pump (server) and gives the information [how many liters]. Then he pull and push the hose into the  the fuel tank and fill the fuel tank (send information) of the car (computer). After that we are on our way (show the results).

          The first web browser was invented by Sir Tim Berners- Lee and it named as WorldWideWeb (later named as Nexus).

Then a lot of web browsers had been released since February 26, 1991 as shown below.

• Mosaic                                                    in 1993

• Netscape Navigator & Communicator    in 1994

• Internet Explorer 1                                  in 1995

• Opera                                                      in 1996

• Mozilla Navigator                                    in June 5, 2002

• Safari                                                      in January 7, 2003

• Mozilla Firefox                                        in November 9, 2004

• Google Chrome                                      in September 2, 2008

Following web browsers are the most popular web browsers nowadays (latest versions).

 Google Chrome (19.0.1084.56)

                      [for Linux, Mac and Windows]                     

   Internet Explorer (9.0.2)                        

                [for Windows only]

    MozillaFirefox(13.0)
                          [for Linux, Mac and Windows]

  These browsers have these user interface elements like,

• Back and forward buttons
• A refresh( /reload ) button
• A stop button to stop reloading(or merged with reload button)
• A home button
• An address bar
• A search bar
• A status bar

Here are some other web browsers.

  Opera                       Safari                Deepnet Explorer

                                              

                                                      Avant Browser

    Maxthon                   Rockmelt                        SeaMonkey

Now let's have a look at the usage share of web browsers from 2009 to present.

      The usage share of a web browser means the percentage of visitors to a group of websites that use a  particular web browser.Let's take an example like this; if Firefox has 30% of usage share , it means that some versions of it is used by 30% of visitors visit the given set of sites.