What are the essential differences Between ext2 - ext3 and ext3 - ext4?

i really want to know the essential differences between those filesystems, for example the inodes pointer Structure and so on!

Thank you

1. Ext2 is the first version of the filesystem created in 1993. It is stable and secure and can support volumes up to 4 TB. It doesn't have any form of journaling. It can be used for partitions that doesn't require journaling functions like boot partitions.

2. Ext3 is more secure and consistent compared to ext2. It has a journaling function that doesn't require a lot of disks access. It is quite slow compared to ext4. It can be used with file with high-variable dimension and server-files.

3. Ext4 have high performances compared to its predecessors. It uses RAM to optimize read/write operations limiting access time. It is suggested for desktop use but not so recommended for servers (considering its young age).