Boot sector concept in linux unlike windows

I dont understand? Linux will install from CD straight to a brand new hard disk.  The process may be different but that is because it is different!
What is the question? Give example

in addition  to primary and extended partition, we also create boot partition in linux unlike windows, why is that?
Sham

A boot partition is just a Primary partition than is marked as bootable. It is not a different kind of partition.

The boot partition is a place to keep kernel images for system booting, just like MBR in Windows. It can be put with root partition under /boot directory, if there was not a separated partition.

The key is in your title:  "linux unlike windows"

Don't expect linux, which is modeled after Unix, to act or be like Windows.  From the very foundation  they are different.

There is a big difference in linux and windows. However the boot sector partition is used to store linux loader (LILO).

When LILO is told to boot a Linux kernel it reads it directly from the disk. LILO needs to be run to generate a new map file. A new boot loader has been designed to overcome this problem.

There are various definitions going on in this thread.  

Boot partition:  
- a partition marked as "bootable" or "active"  (Linux doesn't really care if it is marked that way or not.)
- a separate partition to hold the kernel images to boot from.  (Not as common as it once was and not *needed* as a separate partition, but can be useful to separate it out from the rest of the system.
- The MBR.  This is not actually a partition, but a space on the disk prior to the first partition to hold the initial boot loader (Could be NTLDR, LILO, GRUB, or ....)

The question is what does mohet01 really mean?  Also, it varies between installers for the various Linux flavors.

in addition  to primary and extended partition, we also create boot partition...

There is no such thing.  There are only primary and extended partitions on the disk (and the MBR before the partitions).  For Linux, if what is contained within one of the partitions is mounted on "/boot" it would be definition #2 above.

probably referring to the grub loader.. and how to set it .. in boot sector etc

Depending on either installation type you use Linux needs a FAT partition for installation as windows does not. Windows needs either FAT32 or NTFS formatted partitions to run. Windows does not come with a boot menu. Certain versions of linux come with boot menu's like lilo,grun, etc. Not entirely sure what your question is, but this sounds to be close enough what your asking.

@Russell_Venable - Linux does NOT need any FAT partition for installation.  I don't know where you get your information, but this is just flat out untrue.

@mccracky, It sure as hell does not run on a NTFS!! My flavor of linux runs on FAT so you are wrong sir! Linux also runs on FAT32 as well! BOTH are FAT!!! Actually the information comes straight from the community. So I dont know where you have been looking at your information. If you ever went through the CEH, CNE or any other of the certification courses you would know this..... There is only 4 different partition types Fat16(FAT), FAT32, NTFS, and HPFS(OS/2). I have ran linux and many other Operating systems to know that when you install linux as a partition it must formated to some type of FAT format it even says it in the installation guide!!! Are you mad?

@Russell_Venable - You are showing your ignorance, sir.    

Please read up on the difference between partitions and file systems. "Fat16(FAT), FAT32, NTFS, and HPFS(OS/2)" are file systems, not partition types.  Also, there are many more file systems than just "Fat16(FAT), FAT32, NTFS, and HPFS(OS/2)"  Start your reading with these links:

http://en.wikipedia.org/wiki/List_of_file_systems
http://en.wikipedia.org/wiki/Comparison_of_file_systems

And for the various "partition types":
http://www.win.tue.nl/~aeb/partitions/partition_types-1.html

I never said it was a partition type I said it was as a format. A type of file system. I'll take a hit on the partition types. I was thinking more on basic lines. Most people dont use those system types. As far as your trying to decipher my statement. Be very careful who you call ignorant. I know a lot more information then you currently know about me. To make a quick decision based on this is your fault and your ignorance. You never even clarified in your defense about FAT. All talk and no walk.

Hello
As per the update , boot Partition has kernel images, can  u name the image file?
Sham

(This is almost starting to sound like an exam or homework question.)

Short answer, yes.  

What do *you* think?  What have you done so far?  What do you really need to know?

Hello
I would like to understand why I create boot partition that I did from many years without knowing the exact reason?
What goes into that partition?
Sham
 

The whole point for partitioning is to split the drive and utilize its memory as multiple hard drives so you can have one system on one partition and pretty much w/e you want to place on the other one that was split into. You can also use a separate partition to make the main file system run more efficiently, store a backup image for recovery, system diagnostic tools, there are so many different ways to use it.

For security, some machines unmount the /boot partition after things are up and running, if I recall correctly.

Historically, separate partitions were used to reserve space on the hard drives and not allow other systems to encroach on that space.  That's one reason some put /var on a different partition--if a runaway process starts filling up all the logs, it won't affect the whole system and fill the whole disk, but just the /var partition.  The same reasoning for the /tmp partition.  /usr/local and /home are typically separate partitions on some systems to save those parts across an OS upgrade.

Some of the historical reasoning is still valid and others are no longer as necessary with the size of disks one usually gets today.

Hello
With respect to mccracky point, if /boot is unmounted  after os start, how do we restart the machine, because /boot is not accessible during restart
Sham

done