Difference between Public Private and Hybrid Cloud

Parameter	Public Cloud	Private Cloud	Hybrid Cloud
Definition	If a cloud infrastructure is made available to general public or a large industry group than it is called Public Cloud.	If a cloud infrastructure is operated solely for an organization than it is called Private cloud.	Composition of two or more clouds (Private, Public, and Community) is called hybrid Cloud. It is the composition of at least one public cloud and at least one private cloud.
Users	Can be used by any internet user on pay per usage basis.	Used by only members of the organization.	It is used by the organizations that are willing to push part of their workloads to public cloud.
Advantage	Good test/development environment for applications that scale too many servers.	Security least is very low because cloud users are very much limited.	Operational flexibility, run mission critical on Private cloud, tests on public cloud.

Difference between Wi-Fi and Wi-Max

Parameter	Wi-Fi	Wi-Max
Acronym for	Wireless Fidelity	World Interoperability for Microwave Access
Description	It is a wireless technology that allows any electronic device to exchange and transfer data wirelessly.	It a wireless technology which delivers carrier class, high speed wireless broadband at low cost and covering large distance than Wi-Fi.
IEEE Standard	IEEE 802.11	IEEE 802.16
Implementation	It is basically an implementation of wireless Local Area Connection within a small building, a college, or an institutional building.	It is a wireless broadband metropolitan technology whose objective is to interconnect houses, buildings, or even hot spots to allow communication between them or with other networks.
Cost	Can be implemented by using low cost access pints.	Wi-Max technology requires costly infrastructure.

Difference between AT89C51 AT89C52 and AT89C2051

Parameter	AT89C51	AT89C52	AT89C2051
Flash Memory Size	4K Bytes of In-System Reprogrammable Flash Memory	8K Bytes of In-System Reprogrammable Flash Memory	2K Bytes of Reprogrammable Flash Memory
Endurance	1,000 Write/Erase Cycles	1,000 Write/Erase Cycles	10,000 Write/Erase Cycles
Data Memory Size	128 X 8 bit internal RAM	256 X 8 bit internal RAM	128 x 8-bit Internal RAM
Operating Voltage	5V (up to 6.6V)	5V (up to 6.6V)	2.7V to 6V
Programmable I/O Lines	32	32	15
Timers/Counters	Two 16 bit	Three 16 Bit	Two 16 bit
Interrupt Sources	Six	Eight	Six

Difference between LED and OLED display

Parameter	LED	OLED
Acronym for	Light Emitting Diode	Organic Light Emitting Diode
Description	It is a flat panel display that uses array of light emitting diodes as video display.	It is also a type of LED in which organic compound is used as emissive electroluminescent layer to emit light when electric current is supplied to it. These OLEDs are self illuminating.
Brightness	LED displays can get extremely bright and have slight advantage.	OLED display can also produce brighter displays but shining OLED pixels to maximum results in reduced pixel life.
Flexibility	Hard Material is used as substrate and can not be used to make flexible displays.	OLED can be fabricated on plastic substrates and can be used for making roll up display and can be embedded in cloths in future.

Difference between IDE SCSI and SATA interfaces

Characteristics	IDE	SATA	SCSI
Acronym For	(IDE) interface	Serial ATA	Small Computer System Interface
Developed in	1986	2003	developed in 1978 and publicly disclosed in 1981
Pins Used	40 Pins	7 Pins (3 grounds and 4 active data lines in two pairs)	50-pin, 68 pin, and 80-pin
Data Transfer Rate	16 MB/s originally later 33, 66, 100 and 133 MB/s	SATA 1.0–> 150 MB/s, SATA 2.0–>300 MB/s,SATA 3.0 –>600 MB/s	Ultra-640 SCSI: 640 MB/s or 5120 Mbit/s
Supported Devices per Cable	Two	One	Sixteen

Difference between LILO and GRUB

Characteristics	Lilo	GNU GRUB
Stands For	Linux Loader	Grand Unified Boot Loader
Developer	Erich Boleyn	Werner Almes Berger(1992-1998)
License	BSD(Berkeley Software Distribution)	GPLv3(Grand Public License Version 3.0)
Configuration Change	Any changes made to lilo.conf are not read at boot time and MBR needs to be refreshed.	There is no need to re-install GRUB to MBR or a Partition after changes to configuration file.
Boot Selection	It can support 16 different images at boot time.	It uses scrollable screen and can easily control 150 or more boot choices by adding them to menu.lst

Difference between Peer to Peer and Client Server Data Model

Parameter	Peer to Peer Model	Client Server Model
Definition	It is the Network Model, in which all nodes on the network are treated as peers that can work either as client or server depending upon that whether it is providing service or getting service.	It is the Network model in which there is one main controller (Server) which provides services to all connected nodes (Clients).
Network Joining	System must join network of peers and must register itself with centralized lookup service.	System must be joined to server to request services.
Service Request	If a peer is working as client than it must first discover that peer which is providing that service and hence uses a broadcast request system.	All the requests of clients are served by Server only.