What is File Management in computer

File Management 

File, a group of related information. Each file has a name, which specified (refer) are used. File management is an important aspect of any operating system, which stores data and programs from secondary storage device for managing serves him. File Management System is responsible for the following functions-the 

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- Logical file for the address mapping of the physical disk addresses.

- Disk space management, for allocation and de-allocation.

- To keep track of all files in the system.

- Sharing and Protection for Files. 

File

Any file, is a collection of bits or bytes or sequence of records. A file any application, report, or an executable program that can be used to store library functions.

Directory

Most operating systems is treated as a file in the directory. Directory holds any of its related files. No one hierarchical directory or directories can be a flat directory. They are flat directories are directories, the root directory holds all the system files and does not contain any sub-directory. Hierarchical directories, directories and sub-directories are a group. Most of the files are arranged in a hierarchical directory. 
Disk Organization
Information stored on a disk in the disk drive number, surface, and is specified by track. Disk platter is made of. Each platter has two surfaces. So if a disk platter 6, so it will be 12 surfaces. But read-write work surfaces come into operation only 10, because the top surface and the bottom of the platter underneath the platter surface can not be read-write operation. In all vertical platter together, make up the cylinder. Disk surface is divided into tracks and the tracks are left in the sector. Information on the disc is stored as blocks in a track. Sector size must be equal to the size of the blocks.
Disk Space Management
Maintain a list of free-spaces of the operating system disk, allowing the unused disk-blocks of disk tracks. To create a new file search is a list of free disk space and free disk space is allocated to the new file. Size of the new file allocate The amount of disk space is removed from the list of free disk space. So when a file is deleted, the disk space used by the files in the list of free disk space is added. 

Bit vector

Most of the free space on the disk is implemented as a bit vector or bitmap. Bit-vector method, each block of the disk is represented by a bit.

Disk Allocation Method

contiguous Allocation

Linked Allocation

Indeksd Allocation

File Protection

Multiuser environment necessary to the security of the file is more than the sharing of files is by our users. Various protection mechanisms are used to protect files are:

Password

Access List

Access Group