FileShare Enumeration specifies the level of access permitted for a file that is already in use.

Delete

It allows subsequent deleting of a file. 

Inheritable

It makes the file handle inheritable by child processes.  This is not directly supported by Win32.

None

It declines sharing of the current file.  Any request to open the file (by this process or another process) will fail until the file is closed. 

Read

It allows subsequent opening of the file for reading.  If this flag is not specified, any request to open the file for reading (by this process or another process) will fail until the file is closed. However, additional permissions will still be needed to access the file, even if this flag is specified. 

ReadWrite

It allows subsequent opening of the file for reading or writing. If this flag is not specified, any request to open the file for reading or writing (by this process or another process) will fail until the file is closed.  However, additional permissions will still be needed to access the file, even if this flag is specified. 

Write

It allows subsequent opening of the file for writing.  If this flag is not specified, any request to open the file for writing (by this process or another process) will fail until the file is closed. However, additional permissions will still be needed to access the file, even if this flag is specified.