File System type ids in hex number in Linux

File System type ids in hex number in Linux

Here's the list of hexadecimal partition identifiers:

http://www.win.tue.nl/~aeb/partitions/partition_types-1.html

Just to clarify, Linux is not the only operating system using this system of identifiers.  The list from the above link is used and recognized by various operating systems (Windows, Linux, Unix, etc), boot managers (LILO, grub, etc.), file systems (FAT16, FAT32, NTFS, ext4, etc.), partition managers (EASEUS, Partition Magic, diskpart, etc.) and any other application that uses and manipulates storage information.

There doesn't seem to be any official explanation as to why partition IDs are in hexadecimal.  Since you asked for insights, my personal opinion is this: 

All data is represented as bits (binary digits) in modern computers.  We can think of Partition IDs as simply data composed of 8 bits.  Why 8 bits?  Because memory was so expensive in the early days of computing that they have to do whatever they can to conserve it.  And besides, 28 = 256 unique IDs which computer engineers at that time thought would be enough to identify any number of partition types that would be developed in the future.  The IDs are expressed in hexadecimal because it is easier for us humans to read, write, and understand hexadecimal rather than binary.

Hope this helps!