how is the location of inodes in the physical disk.
are they sequential like:
bootblock|superblock|inode1|inode2| ....| datablock1|datablock2|datablock3

or are they distributed among data blocks like:

bootblock|superblock|inode1|datablock1|inode2|datablock2|datablock3|inode3
|datablock4

Also along with that could someone explain what is an inode.

hi,

Inode is the information about the file. It will be having info like permission, no of links ( hard link), time stamps (change time, modify time and access time), owner, group, size.

This information will be present in the data block ( disk). Per block the the no of inode no are fixed. By getting the inode no and the filesystem it will make offset such that it will be accssing the requried inode information and will be put into incore inode table to use further.

This depends on filesystem, e.g. for ext3 look at http://en.wikipedia.org/wiki/Ext3