Most file systems were created for use on old fashioned spinny hard drives, not the flash storage all smartphones and many notebooks now take advantage of. Samsung has taken the liberty of creating a new file system specifically made for NAND flash storage, probably targeted at Android smartphones. It is called F2FS, or Flash-Friendly File-System.
Companies can make big money on licensing file systems, we’ve seen it done before. Samsung instead opted to open source it and submit it to the Linux kernel. This not only will help the community, but will help the file system possibly make it to Android devices. All I can do is give praise to Samsung for open sourcing an in-house file system.