• Separates OS and program files to optimize interaction with the operating system.
• Better organization to allow frequently-used data and programs to be near each other.
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• Allows multi-boot setup options.
• Protects and isolates files.
• Enables image backups to be made of only the operating system and installed software.
Cons
• Reduces the total space available for storage on the drive.
• Reduces performance on HDDs when accessing data frequently on different partitions (does not affect SSDs).
• Prevents using the whole disk capacity for a single large folder/file/application.