Some filesystems (like btrfs and ZFS) support comression on the filesystem level, where each block is compressed with some algorithm automatically, completely transparently to applications.
Most modern CPUs are fast enough at the light levels of compression that is used, that usually its also faster, because you read less data, and the read + decompress time is often lower than how long it would have taken to just read more data; though of course that depends on what data exactly, but overal its often faster (though usually its not by a very significant amount) for most average uses.
Some filesystems (like btrfs and ZFS) support comression on the filesystem level, where each block is compressed with some algorithm automatically, completely transparently to applications.
Most modern CPUs are fast enough at the light levels of compression that is used, that usually its also faster, because you read less data, and the read + decompress time is often lower than how long it would have taken to just read more data; though of course that depends on what data exactly, but overal its often faster (though usually its not by a very significant amount) for most average uses.