Difference between Hard Disk and Floppy Disk

Disk

A magnetic Disk is a disk made up of metal or plastic which is used for storing data. Normally both side of the disc is used for storing data. A magnetic Disk is classified as 

in main secondary device Various types of secondary devices are there like floppy disk and hard disk. Hard disk can be considered as being made up multiple floppy disks put one above the other

Floppy Disk

Floppy disk is made up of round piece of plastic material coated with a magnetized recording material.

The surface of a floppy disk is made of concentric circles called tracks. Disk  can be considered to be consisting of several surfaces, each of which Consisting of tracks.

The tracks are normally numbered from as the outermost track with the number increase inwards. Each track is divided into a no of sectors of equal size Sector capacities may vary, but typically a sector can store up to 512 bytes

• Double-sided floppy have two sides on which data can be recorded, so given sector is specified by a components of address, surface no, track no, and sector no
• Floppy disk is a magnetic disk that contains a single plastic disk. In the initial days of the computer invention it was used as the main storage device, later on, it was used for carrying data from one computer to another but nowadays it is almost not used. It requires a floppy drive for operation.

Hard Disk

Hard Disk Mechanism

Hard disk surface is also made of concentric circles called tracks. Each track is divided into sectors of equal size. The disk drive for hard disk and its read/write mechanism is shown in fig. (1.3). Read/ write head for each surface connected to arm Arm can move in or out to position itself on any track while disk rotates at a constant speed e.g 
Hard Disk is a magnetic disk made of aluminium. It is used as the main storage device on the computer. It uses a metallic disk which is known as a platter. Both sides of the disk are used for storing data except the upper side of the uppermost disk and the lower side of the lowermost disk. Magnetic oxide is used to coat the data storing surface. 

1.  Read a block
2.  It is translated into a sector address surface=1, track=10, sector-5. This is called
3. Read/write heads current position’s address is current address, ie. Surface =0, track=7,sector =7.
4. Move the arm in or out position on correct track. In this e.g. move arm inwards from track 7 to track 10. The time taken to move to correct track is called seek time.
5.  Wait until desired sector comes under r/w head as disk rotates. Time to reach w particular sector on track is called rotational delay or latency.
6.  Activate R/W head for appropriate surface and read data. The time taken for this operation is called transmission time.

Difference between Hard Disk and Floppy Disk :

S. No.	HARD DISK	FLOPPY DISK
1.	It is magnetic disk made of aluminium.	It is magnetic disk made of plastic.
2.	It is used as main storage device of computer.	Initially it was used as main storage device but now-a-days it is not used.
3.	It uses 2-4 metallic disk called platter.	It contains single plastic disk.
4.	Data storing surface is coated by magnetic oxide.	Data storing surface is exposed.
5.	It is reliable.	It is not as reliable as hard disk.
6.	Storage capacity is very high.	Storage capacity is low.
7.	Stores data at high speed.	Stores data at low speed.
8.	Retrieves data at high speed.	Data access relatively slow.
9.	Data can not be damaged or corrupted.	Data cane be damaged or corrupted.
10.	It is not portable easily.	It is easily portable.
11.	Weight is heavier than floppy disk.	It has lighter weight.
12.	It is very costly compared to floppy disk.	It is quite cheap.
13.	Security from viruses is better.	Susceptible to viruses.
14.	It is widely used now-a-days.	It is very less used almost not used.
15.	It is more resistant to damage caused by dust and heat.	It is less resistant to the damage caused by dust and heat.
16.	When a computer is turned on, hard disk drives begin to rotate and then rotate continuously.	To serve the purpose of reading or writing data, floppy disk drives begins to rotate.
17.	The upper side of the top disk and lower side of the bottom disk cannot be used to store data in the platter due to easy scratching of these surfaces.	The storing of data is possible on both sides of the floppy disk.