This is a quick reference to the Linux file system.
The common file systems used on new Linux installations are:
Ext4 allows to shrink and expand volumes, whereas XFS only allows to expand volumes.
Both ext4 and xfs are journalling file systems which means when writing/saving files to a disk, the file system will save somewhere else temporarily until the full file has been successfully saved. It makes a log of the status of the write and will complete save operations by checking the log. This approach cuts down on corrupted files.
Deleting and Editing Files
Linux allows to delete and edit open files. This is done by still linking the files to the OS even if it deleted. You can also move files whilst being partially downloaded or delete programs that are currently running without crashing.
Linux file systems are designed to minimise fragmentation by keeping sufficient space between files on the hard disk. This allows files to grow and still be written to the same location on the hard disk. Overtime though the file system can become fragmented where tools are provided for de-fragmentation.