PARTITION TABLE (MBR or GPT)

              MBR (Master Boot Record) and GPT (GUID Partition Table) are two different ways of storing the partitioning information on a drive. This information includes where partitions start and begin, so your operating system knows which sectors belong to each partition and which partition is bootable. This is why you have to choose MBR or GPT before creating partitions on a drive.

MBR’s Limitations

              MBR standards for Master Boot Record. It was introduced with IBM PC DOS 2.0 in 1983.

              It’s called Master Boot Record because the MBR is a special boot sector located at the beginning of a drive. This sector contains a boot loader for the installed operating system and information about the drive’s logical partitions

             The boot loader is a small bit of code that generally loads the larger boot loader from another partition on a drive.

              MBR works with disks up to 2 TB in size, but it can’t handle disks with more than 2 TB of space.

• Supports 4 paritition
• One partition can be a extended partition
• Partition Limit of 2TB usable 

GPT’s Advantages

              This system doesn’t have MBR’s limits. Drives can be much, much larger and size limits will depend on the operating system and its file systems. GPT allows for a nearly unlimited amount of partitions, and the limit here will be your operating system — Windows allows up to 128 partitions on a GPT drive, and you don’t have to create an extended partition.

• supports 128 partition
• supports zettabyte hard disk
•  required for booting

         it uses Unified Extensible Firmware
         it needs 64bit hardware

           On an MBR disk, the partitioning and boot data is stored in one place. If this data is overwritten or corrupted, you’re in trouble. In contrast, GPT stores multiple copies of this data across the disk, so it’s much more robust and can recover if the data is correupted. 

          GPT also associated with UEFI(Unified Extensible Firmware Interface) — UEFI replaces the clunky old BIOS with something more modern, and GPT replaces the clunky old MBR partitioning system with something more modern. It’s called GUID Partition Table because every partition on your drive has a “globally unique identifier,” or GUID — a random strong so long that every GPT partition on earth likely has its own unique identifier.

BIOS uses MBR and UEFI uses GPT

What is spam mails

           Spam" (the term junk mail is also used) refers to the sending of unsolicited bulk e-mails.

            The word "spam" comes from the name of the lunch meat sold by the company Hormel Foods. The association of this word with abusive e-mails comes from a Monthy Python sketch (Monty Python's famous spam-loving vikings) that takes place in a viking restaurant whose speciality is Spam. In this sketch, whenever a customer orders a different dish, the other customers start to sing "spam spam spam spam spam..." in chorus so loud that the poor customer can't be heard! 

so why sending spam ?

                   one word "advertisement"

Many spam emails contain URLs to a website or websites.The most popular spam topic is "pharmacy ads" which make up 81% of email spam messages.It's beleive that the advance fee fraud spam such as the Nigerian "419" scam may be sent by a single guy/gal from somewhere.

There are big spam companies too .

                     The computers in Ralsky's basement control 190 e-mail servers -- 110 located in Southfield, 50 in Dallas and 30 more in Canada, China, Russia and India. Each computer, he said, is capable of sending out 650,000 messages every hour -- more than a billion a day -- routed through overseas Internet companies Ralsky said are eager to sell him bandwidth.

How to stop spam ?

                   The best technology that is currently available to stop spam is spam filtering software.
More advanced filters, known as heuristic filters and Bayesian filters, try to take this simple approach quite a bit further to statistically identify spam based on word patterns or word frequency.