What are the advantages and disadvantages of them?

Ext 3 is ext2 plus journaling so if you have a power outage or something that suddenly shuts off your computer without cleany unmounting file sytems it will reboot faster.

If you really want to learn about ext3 go here
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The ext3 filesystem is a journaling extension to the standard ext2 filesystem on Linux. Journaling results in massively reduced time spent recovering a filesystem after a crash, and is therefore in high demand in environments where high availability is important, not only to improve recovery times on single machines but also to allow a crashed machine's filesystem to be recovered on another machine when we have a cluster of nodes with a shared disk.
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