Some Important Differences of Computer Science of Grade XI

Analog Computer & Digital Computer

Analog Computer	Digital Computer
The computer which is based on continuous data is known as analog computer.	The computer which is based on discrete data is known as digital computer.
It measures only physical or natural quantities such as water flow, current and voltage.	It is based on digits that are 0 and 1 or OFF and ON state.
It is used for specific purposes.	It is used for general purposes.
These computers are suited for physics and engineering.	These computers are suited for graphical works, documentation, business and industrial processes.
Has no storage or memory capacity.	Has high storage or memory capacity.
Cost is low compared to digital computers.	Cost is high compared to analog computers.
E.g.: Thermometer, Speedometer etc.	E.g.: IBM PC, MAC Book etc.

Primary & Secondary Memory

Primary Memory	Secondary Memory
Low storage capacity.	High storage capacity.
Used for short term basis.	Used for long term basis.
Also called Main memory.	Also called Auxiliary memory.
Faster than Secondary memory.	Slower than Primary memory.
It is temporary / permanent memory.	It is permanent memory.
Expensive than Secondary memory.	Cheaper than Primary memory.
E.g.: RAM, ROM etc.	E.g.: Magnetic drums, tapes, disks etc.

RAM & ROM

RAM	ROM
Stands for “Random Access Memory”.	Stands for “Read Only Memory”.
Volatile memory.	Non-volatile memory.
RAM’s data can be modified.	ROM’s data cannot be modified.
Cheaper than ROM.	Expensive than RAM.
Capacity can be extended.	Capacity cannot be extended.
Faster than ROM.	Slower than RAM.
There is read and write property.	There is only read property.

SRAM & DRAM

SRAM	DRAM
It stands for “Static Random Access Memory”	It stands for “Dynamic Random Access Memory”
Mostly formed of transistors.	Mostly formed of capacitors.
It has low density of data.	It has high density of data.
Expensive than DRAM.	Cheaper than SRAM.
Doesn’t require periodic refreshing.	Requires periodic refreshing.
Uses cache memory.	Uses main memory.
Consumes less electrical power.	Consumes high electrical power.

Impact & Non-Impact Printers

Impact Printers	Non-Impact Printers
The head strikes ink coated ribbon to print information.	The thermal, chemical or optical techniques are applied to print information.
Noisy.	Less noisy.
Slow.	Fast.
Poor quality printers.	High quality printers.
Normally outdated.	Popular at the moment.
E.g.: Dot-matrix, Daisy wheel etc.	E.g.: Thermal, Laser, Ink-jet printers etc.

Package & Tailored Software

Package Software	Tailored Software
They are designed mainly by software companies to generalize the tasks.	They are specific purpose software.
Assembly, machine and high level language is used.	High level language is used.
They are expensive.	They are less expensive.
License is required to publish.	License is not required to publish.
Long time is required to create.	Short time is required to create.
Skilled programmers are required.	Less skilled programmers are required.
E.g.: MS-Office package, Maya etc.	E.g.: Hotel Management System, Cyber Café security.

Compiler & Interpreter

Compiler	Interpreter
It translates high level language into machine language at single attempt.	It translates high level language into machine language by one instruction at a time.
It finds the syntax errors after compiling the whole program.	It finds the syntax errors after translating a line of program at a time.
It is difficult to trace errors and causes of the errors.	It is easy to trace errors and causes of the errors.
Compiling process is faster than interpreter.	Interpreting process is faster than compiler.
More efficient than interpreter.	Less efficient than compiler.
Creates object code.	Doesn’t create object code.
E.g.: C#, VB.NET, JAVA etc.	E.g.: BASIC, LISP, PROLOG, COBOL etc.

Program & System Flowchart

Program Flowchart	System Flowchart
It is used for designing small sized logical mathematical problems.	It is used for designing a large sized real world problem.
Gives specific view of control flow of a program.	Gives the board overview of system.
Shows the instruction flow of a program.	Shows the data flow of a program.
Program flowchart is designed by programmer.	System flowchart is designed by system designer.