Briefly explain the main differences between ext2 and ext4 file systems.

Main differences between the ext2 and ext4 file systems:

• ext2 is an older file system that does not support journaling, which can lead to longer check times after crashes.
• ext4 is a modern version with journaling support, increasing reliability and recovery speed.
• ext4 supports larger data and file sizes, improved performance through extent indexes and delayed allocation.
• ext4 has additional features such as integrity checking, improved fragmentation management, and online expansion capabilities.

Thus, ext4 is a more reliable and high-performance file system compared to ext2.