You can store same data, but also make it take less or much less space on your storage without needing to make an file archives such as ZIP/RAR & read faster by using lossless compression available in some file systems (which is really useful for HDDs)
File systems that support file compression are file systems like: BTRFS, ZFS, NTFS
I personally use ZSTD compression on BTRFS on my main drives including my archival HDD, I was surprised by how much free space I got on my game partition on my NVMe SSD after I decided to enable compression & use btrfs defrag to compress files, I didn't even had to delete any games!
(the reason why I ran btrfs defrag is because if you mount your partition with a compression command, it only compresses the newly written files, existing files need to be compressed with defrag command)
But why files can be readed faster than if they were uncompressed?
the reason why they can be readed faster than uncompressed is due to it being readed in compressed form & decompressed by CPU faster rather than directly reading the higher amount of data when files are uncompressed if files are stored on a slower drive like HDD