RAM Vs ROM

RAM	ROM
RAM stands for Random Access Memory.	ROM stands for Read Only Memory.
In RAM data can be read/write at any time during the operation of system.	In ROM data can be read only. One cannot write in ROM after the chip is ready to use.
It is a volatile memory i.e. its contents are lost when the device is powered off.	It is a non-volatile memory i.e. its contents are retained even when the device is powered off.
Its accessing speed is faster.	Its accessing speed is slower.
The price of RAM is comparatively high.	The price of ROM is comparatively low.
The size of RAM chip is larger than ROM chip.	The size of ROM chip is smaller than RAM chip.
Types of RAM are Static RAM (S-RAM) and Dynamic RAM (D-RAM).	Types of ROM are Programmable Read Only Memory (PROM), Erasable Programmable Read Only Memory (EPROM), Electrically Erasable Programmable Read Only Memory (EEPROM) etc.

LAN Vs MAN Vs WAN

Parameters	LAN	MAN	WAN
Full Form	Local Area Network	Metropolitan Area Network	Wide Area Network
Geographical Spam	Building or campus	City	Country
Ownership	Privately Owned	Public or private	Public
Setup Cost	Cheap	Moderate	High
Range	2500 m	200 km	Beyond 200 km
Error Rate	Low	Moderate	High
Transmission Media	Wires	Wires or telephone lines	Satellite
Speed	High	Moderate	Low
Propagation Delay	Short	Moderate	Long
Mode of Operation	Broadcasting	Broadcasting and switching	Switching
Network Devices	Bridge, hub, repeater and switch	Gateway router	Gateway router
Example	College campus or industry	Cable TV	Internet

Circuit Switching Vs Packet Switching

Circuit Switching	Packet Switching
Dedicated path is created between two points.	Virtual path is created between two points.
Bandwidth is fixed.	Bandwidth is dynamic.
The links that make a path are dedicated and cannot be used by other connections.	The links that make a route can be shared by other connections.
Congestion can occur at setup time.	Congestion can occur on every packet.
Path followed by packets is always same.	Path followed by packets is may or may not be same.
It is highly reliable.	It is less reliable.
It is implemented at Physical layer.	Datagram Switching is implemented at Network layer and Virtual Circuit Packet Switching is implemented at Data Link layer.
It requires call setup.	It does not require call setup.
Store and forward transmission is not used in Circuit Switching.	Each node may store incoming packets temporarily and forward them later.

Call By Value Vs Call By Reference

Call By Value	Call By Reference
In this, the function is called by passing value of variable as argument.	In this, the function is called by passing address of variable as argument.
Arguments passed by value can be variables, literals or expressions.	Arguments passed by reference can only be variables.
In this, copy of actual arguments is created and passed to function.	In this, no copy of actual arguments is created.
Actual and formal arguments are created in different memory locations.	Actual and formal arguments are created in same memory locations.
Any changes made to the formal arguments will have no effect on actual arguments.	Any changes made to the formal arguments will have immediate effect on actual arguments.
No pointers are used in this approach.	The pointers are used in this approach.
It is a slow way of calling functions.	It is a fast way of calling functions.
Program: #include<iostream> using namespace std; int swap(int, int); int main() { int a=4, b=10; cout<<"Before Swaping:"; cout<<"\nValue of a="<<a<<" & b="<<b; swap(a,b); return 0; } int swap(int x, int y) { int temp; temp=x; x=y; y=temp; cout<<"\nAfter Swaping"; cout<<"\nValue Of a="<<x<<" & b="<<y; }	Program: #include<iostream> using namespace std; int swap(int *, int *); int main() { int a=4, b=10; cout<<"Before Swaping:"; cout<<"\nValue of a="<<a<<" & b="<<b; swap(&a,&b); return 0; } int swap(int *x, int *y) { int temp; temp=*x; *x=*y; *y=temp; cout<<"\nAfter Swaping"; cout<<"\nValue Of a="<<*x<<" & b="<<*y; }

Synchronous Time Division Multiplexer Vs Asynchronous Time Division Multiplexer

Synchronous Time Division Multiplexer	Asynchronous Time Division Multiplexer
Multiplexer allocates same time slot to each device.	Multiplexer does not allocate same time slot to each device.
Number of slots per frame is equal to number of input devices.	Number of slots per frame are less than the number of input devices.
Number of devices supported by synchronous time division multiplexer are less than asynchronous time division multiplexer.	Asynchronous time division multiplexer supports more devices than synchronous time division multiplexer.
Number of time slots in a frame is based on number of input devices.	Number of time slots in a frame is based on statistical analysis.
It does not guarantee that the full capacity of link is used.	It guarantees that the full capacity of the link is used.
Time slots are preassigned.	Time slots are not preassigned.

Zeolite Process Vs Lime Soda Process

Zeolite Process	Lime Soda Process
Operating cost is lower as zeolites are regenerated with cheap NaCl.	Operating cost is higher as costly chemicals such as lime, soda, coagulants are used.
The treatment plant size is compact and small.	The treatment plant size is bulky and large.
It produces water of 10-15 ppm hardness.	It produces water of 15-50 ppm hardness.
Treated water contains a large amount of sodium salts.	Treated water contains lesser percentage of sodium salts.
Acidic water cannot be softened as acidic water attacks zeolite.	Acidic water can be softened.
The water should be free from turbidity as the suspended impurities can block the pores of zeolite.	Turbid water can be softened.
No sludge is formed, so no problem of sludge disposal.	Large quantity of sludge is formed.
This process removes only Ca2+ and Mg2+ ions in solution. It does not remove anions (Cl-, SO4-2, HCO3-) from solution.	It removes cations and anions from the solution.
Treated water contains more NaHCO3 which is not suitable for boilers.	Treated water is free from NaHCO3 and is suitable for boilers.
It automatically adjusts itself to water samples of different hardness.	Frequent control and adjustment of reagents is needed.

Combinational Circuit Vs Sequential Circuit

Combinational Circuit	Sequential Circuit
The output doesn’t depends upon previous states.	The output depends upon present inputs as well as previous inputs.
Memory elements are not present in combinational circuits.	Memory elements are present to store the past history of input variables in sequential circuits.
More hardware is required.	Less hardware is required.
These are faster in speed.	These are slower in speed.
These are easy to design as memory elements are absent.	These are difficult to design due to memory elements.
These are expensive.	These are cheap.
Clock circuit is not used in these circuits.	Clock circuit is an essential requirement in these circuits.
Feedback path is not used.	Feedback path is used.
Examples: parallel adders, multiplexers, encoders, code converters etc.	Examples: flip-flops, counters, registers etc.
Block Diagram:	Block Diagram:

Microprocessor Vs Microcontroller

Microprocessor	Microcontroller
Microprocessor is a general-purpose chip that is used to create a multi-function computer or device and requires multiple chips to handle those tasks.	Microcontroller is a highly-integrated chip that contains all the components comprising a controller.
It contains ALU, Control Unit, registers and interrupt circuit.	It contains microprocessor, memory (RAM, ROM), I/O Interfacing circuit and peripheral devices such as A/D converter, Serial I/O, timer etc.
It has many instructions to move data between memory and CPU.	It has one or two instructions to move data between memory and CPU.
It has one or two bit handling instructions.	It has many bit handling instructions.
Access time for memory and I/O devices is more.	Less access time for built-in memory and I/O devices.
Microprocessor based system requires more hardware.	Microcontroller based system requires less hardware reducing PCB size and increasing the reliability.
Microprocessor based system is more flexible from design point of view.	Microcontroller based system is less flexible from design point of view.
Less number of pins are multi-functioned.	More number of pins are multi-functioned.
Microprocessors are most commonly used as the CPU in microcomputer systems.	Microcontrollers are used in small, minimum component microcomputer system performing control-oriented activities.
Example – INTEL 8085, INTEL 8086 etc.	Example – INTEL 8051, Motorola MC68HC11 etc.

Multiplexer Vs Demultiplexer

Multiplexer	Demultiplexer
Many to one configuration is known as Multiplexer.	One to many configuration is known as Demultiplexer.
It is abbreviated in short as MUX.	It is abbreviated in short as DEMUX.
It selects one input and give it at the output. Thus, it is also known as data selector.	It selects single input at one of the output lines. Thus, it is also known as data distributor.
It contains 2n inputs and one output. Out of 2n one input is selected by selection line.	It contains one input and 2n outputs. Out of which one output is selected by selection line where the input line is connected.
Types of MUX are: 2:1, 4:1, 8:1, 16:1 etc.	Types of DEMUX are: 1:2, 1:4, 1:8, 1:16 etc.
Functional block diagram of MUX is as shown:	Functional block diagram of DEMUX is as shown:
Common ICs used for MUX are 74153, 74352, 74151A etc.	Common ICs used for DEMUX are 74139, 74154 etc.
Applications of MUX are data selection and routing, parallel to serial conversion, wave form generation, logic function generator etc.	Applications of DEMUX are in telecommunication to carry signal over long distances.

Memory Mapped Vs Input/output Mapped

Memory Mapped	Input/output Mapped
16-bit device address is used.	8-bit device address is used.
Data is transferred between any general-purpose register and I/O port.	Data is transferred only between accumulator and I/O port.
The memory map (64K) is shared between I/O device and system memory.	The I/O map is independent of the memory map, 256 input devices and 256 output devices can be connected.
More hardware is required to decode 16-bit address.	Less hardware is required to decode 8-bit address.
Arithmetic or logical operations can be directly performed with I/O data.	Arithmetic or logical operations cannot be directly performed with I/O data.
All instructions related to memory can be used for data transfer.	Only IN and OUT instructions can be used for data transfer.
A large number of I/O ports can be interfaced.	Only 256 ports can be interfaced.
Less memory space is available due to partitioning.	Whole address space is available.
The devices are accessed by memory read and memory write cycle.	The devices are accessed by I/O read and I/O write cycle.
Arithmetic and logical operations can be directly performed with I/O data.	Arithmetic and logical operations cannot be directly performed with I/O data.

Thermal Reactions Vs Photochemical Reactions

Thermal Reactions	Photochemical Reactions
Energy of activation is provided by the collisions of molecules.	Energy of activation is gained by the absorption of radiation.
Rate of reaction depends on temperature.	Rate of reaction is independent of temperature and depends on intensity of radiation.
Thermal reaction is accompanied by the decrease in free energy i.e. ΔG is always negative.	Free energy of photochemical reaction may increase as some of radiation energy may be converted into free chemical energy of products i.e. ΔG may be positive or negative.
Intermolecular collisions results in the excitation of all the molecules to almost the same extent.	A single atom or molecule can be promoted to excited state independent of the other species present in the reaction system. So, photochemical activation is highly selective.
To increase the average energy of all molecules, significantly high temperature is required.	Molecules on absorption of radiation are strongly excited and reaction can be carried out easily at low temperature.
These reactions can take place by ionic as well as free radical mechanism.	These reactions generally take place by free radical mechanism.
These reactions are accelerated by the presence of a catalyst.	These reactions may be accelerated by the presence of an additional substance called photosensitizer.

DES Algorithm Vs 3DES Algorithm Vs AES Algorithm

Parameters	DES Algorithm	3DES Algorithm	AES Algorithm
Full Form	Data Encryption Standard	Triple Data Encryption Standard	Advanced Encryption Standard
Created By	IBM in 1975	IBM in 1978	Joan Daemen in 1998
Key Size	56 bits	56*3 = 168 bits (three keys)	128 bits
Block Size	64 bits	64 bits	128 bits
Number of Rounds	16	48	10-14
Attacks	Brute force attack	Theoretically Possible	Side channel attacks
Encryption Software	Fast	Slow	Medium
Time to Encrypt 48KB	7 seconds	21 seconds	13 seconds
Security	Not good	Passing	Secure

8085 Microprocessor Vs 8086 Microprocessor

Parameters	8085 Microprocessor	8086 Microprocessor
Size	It is an 8-bit microprocessor.	It is a 16-bit microprocessor.
Introduced	It was introduced in 1976.	It was introduced in 1978.
Data Bus	It has 8-bit data bus.	It has 16-bit data bus.
Address Bus	It has 16-bit address bus.	It has 20-bit address bus.
Memory Access Capacity	It can access up to 216 = 64KB of memory.	It can access up to 220 = 1MB of memory.
I/O Capacity	It can access 28 = 256 I/O ports.	It can access 216 = 65536 I/O ports.
Clock Speed	It operates on 3MHz, 5MHz or 6MHz.	It operates on 3MHz, 8MHz or 10MHz.
Flags	It has 5 flags (Sign, Zero, Auxiliary Carry, Parity & Carry).	It has 9 flags (Carry, Auxiliary Carry, Zero, Sign, Parity, Overflow, Trap, Interrupt & Directional).
Coprocessor Interface	It does not have coprocessor interface.	It has coprocessor interface.
Pipelining	It does not support pipelined architecture.	It supports two stage pipelined architecture.
Memory Segmentation	It does not support memory segmentation.	It supports memory segmentation.
Transistors	It has 6500 transistors.	It has 29,000 transistors.
Interrupts	It has 8 software interrupts and 5 hardware interrupts.	It has 256 software interrupts and 2 hardware interrupts.
Addressing Mode	It supports 5 addressing modes.	It supports 8 addressing modes.
Operating Mode	It supports single operating mode.	It supports two operating modes: Maximum and Minimum mode.
Multiplexed Pins	It has few multiplexed pins.	It has more multiplexed pins than 8085.
Arithmetic Support	It only supports integer and decimal arithmetic.	It supports integer, decimal and ASCII arithmetic.
Cost	Its cost is low.	Its cost is high.

Active Matrix LCD Vs Passive Matrix LCD

Active Matrix LCD	Passive Matrix LCD
It uses thin film transistors (TFT) that are arranged in a matrix on a glass surface. These tiny switching transistors and capacitors control the voltage at each pixel location.	It uses a grid of vertical and horizontal conductors comprised of Indium Tin Oxide (ITO) to create an image. Each pixel is controlled by an intersection of two conductors.
They are more costly.	They are less costly.
It has high response time.	It has low response time.
It allows the viewer much more freedom to choose his/her viewing angle.	They are best viewed head on and moving to either side to view screen from an oblique angle causes color distortion, dimming and other problems.
They have high refresh rates.	They have low refresh rate.
They display higher resolution.	Resolution is low as compared to active matrix LCD.
They can create gray scale and offers 256 levels of brightness per pixel.	They do not reproduce colors accurately.
They are used in full-color LCD TVs monitors, cell phones etc.	They are used in calculator display or a digital wrist watch where the display contains a limited number of segment and does not require full color.

RICS Vs CISC

RICS	CISC
RICS stands for Reduced Instruction Set Computer.	CISC stands for Complex Instruction Set Computer.
Simple instructions taking one cycle.	Complex instructions taking multiple cycles.
Relatively few instructions.	Wide range of instructions.
Uses simple addressing modes.	Uses complex addressing modes.
Only LOAD/STORES reference memory.	Any instruction may reference memory.
Highly pipelined.	Not pipelined or less pipelined.
Multiple register set.	Single register set.
Complexity is in the compiler.	Complexity is in the micro-program.
Fixed format instructions.	Variable instruction formats.
Instructions executed by the hardware.	Instructions interpreted by the micro-program.
Emphasis on software.	Emphasis on hardware.
Examples: IBM RS6000, MC88100, DEC’s, ALPHA 21064 etc.	Examples: Intel 386, 486, Pentium, Pentium Pro, Pentium II etc.

Data Structure Vs Data Type

Data Structure	Data Type
It is the logical or mathematical organization of data.	It determines type of data stored in variable.
It is a method of organization of data in main memory during processing.	It is a method of describing domain to which a particular item belongs to.
Built in data structures are arrays and records.	Built in data types are integer, character and float.
User defined data structures are stacks, queue and link lists.	User defined data type are structures, union and classes.
It is the collection of basic data types and extension to some structure.	It is the smallest part of data structure which cannot be reduced.

HTML Vs XML

HTML	XML
HTML stands for HyperText Markup Language.	XML stands for Extensible Markup Language.
It was invented in 1990.	It was invented in 1996.
It was designed for creation of web pages.	It was designed for storing and transporting data.
It has its own predefined tags.	In XML, custom tags can be created.
It is a presentation language.	It is neither a presentation nor a programming language.
It is case insensitive.	It is case sensitive.
It does not preserve white spaces.	It preserves white spaces.
It is about displaying data, hence static.	It is about carrying information, hence dynamic.

Directed Graph Vs Undirected Graph

Directed Graph	Undirected Graph
A directed graph is a graph in which the edges in the graph that link the vertices have a direction.	An undirected graph is a graph in which there is no direction in the edges that link the vertices in the graph.
Edges in directed graph are ordered pairs.	Edges in an undirected graph are not ordered pairs.
In-degree and out-degree of each node in directed graph may or may not be equal.	In-degree and out-degree of each node in an undirected graph is equal.
A directed graph cannot be converted to undirected graph.	An undirected graph can be converted to directed graph.
If directed graph is represented by a matrix we may or may not get symmetric matrix.	If undirected graph is represented by a matrix we always get a symmetric matrix.
Example:	Example: