WBBSE Madhyamik Computer Application (Optional) flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

Data vs Information

Data is raw, unprocessed facts and figures such as marks or names. Information is data that has been processed and organised so it becomes meaningful and useful for decision-making.

Stored Program Concept

Instructions and data are both kept in the same memory, so the CPU fetches and executes them in sequence. This idea, credited to von Neumann, underlies modern computers.

Byte and Nibble

A bit is one binary digit. A nibble is 4 bits, and a byte is 8 bits, which can represent 256 different values and usually stores one character.

Binary Place Weights

In a binary numeral, positions from the right have weights 1, 2, 4, 8, 16, 32, 64, 128. Adding the weights where the bit is 1 gives the decimal value.

Volatile Memory

Memory that loses its stored contents when power is switched off. RAM is volatile, which is why unsaved work is lost during a power failure.

Compiler vs Interpreter

A compiler translates the entire source program into machine code before running it and reports all errors together. An interpreter translates and executes line by line, stopping at the first error.

Operating System

System software that manages hardware, memory, files and processes, and provides an interface between the user and the computer. Examples include Windows, Linux and Android.

Firmware

Software permanently stored in read-only memory, such as the BIOS bootstrap loader. It starts the machine and is not normally changed by ordinary users.

Hexadecimal Digits

Digits 0 to 9 plus letters A to F, where A represents 10 and F represents 15. Each hexadecimal digit corresponds exactly to four binary bits.

2's Complement

A signed binary representation obtained by inverting all bits of the number and adding 1. Computers use it to perform subtraction by adding a negative value.

Decimal to Binary Conversion

Divide the decimal number repeatedly by 2, note each remainder, and stop when the quotient is zero. Read the remainders from bottom to top to get the binary number.

ASCII Code

American Standard Code for Information Interchange, a 7-bit character code for 128 characters including letters, digits and control codes. Extended versions use 8 bits.

Algorithm

A finite, ordered set of unambiguous steps that takes input, performs processing and produces output. It must terminate and every step must be clearly defined.

Flowchart Decision Symbol

A diamond-shaped box that asks a yes/no question and has one entry and two exits. Exactly one exit path is followed, depending on the answer.

Dry Run

Manually executing an algorithm step by step with sample data and recording variable values in a trace table, to check whether the logic produces the correct output.

Modulus Operator

The % operator returns the remainder of integer division, so 17 % 5 gives 2. It is commonly used to test divisibility or extract the last digit of a number.

Integer Division

Division of two integer operands that discards the fractional part, so 7 / 2 gives 3 in C or Java. At least one float operand is needed for a decimal result.

While vs Do-While

A while loop tests the condition before executing the body, so the body may never run. A do-while loop tests after the body, so it runs at least once.

Zero-Based Indexing

Array positions are numbered from 0, so an array of n elements has valid indices 0 to n−1. Using index n causes an out-of-bounds error.

Linear Search

Searching an array by comparing the target with each element from the first position onwards. It works on unsorted data but may examine every element.

String Length

The number of characters stored in a string, excluding the terminating null character in C. It is found by counting characters until the terminator is reached.

LAN

Local Area Network, covering a limited area such as a room, building or campus. It offers high speed and is usually owned by one organisation.

Star Topology

A network layout in which every node connects to a central hub or switch. A single cable fault affects only one node, but failure of the centre stops the network.

DNS

Domain Name System, a service that converts human-readable domain names such as example.com into numeric IP addresses so that browsers can reach the correct server.

Router

A network device that forwards data packets between different networks using IP addresses, choosing the best path for each packet to reach its destination.

Phishing

A fraudulent email, message or website that imitates a trusted organisation to trick users into revealing passwords, card numbers or other sensitive information.

Digital Footprint

The permanent trail of information a person leaves online through posts, searches, comments and uploads. It may be copied or archived even after the user deletes it.

Firewall

Hardware or software that monitors network traffic and allows or blocks it according to rules, protecting a computer or network from unauthorised access.

Cloud Computing

Delivery of computing services such as storage, servers and software over the Internet on demand, so users avoid buying and maintaining their own hardware.

Internet of Things

A network of everyday physical devices fitted with sensors and network connections that collect and exchange data, such as smart meters, wearables and connected appliances.

Artificial Intelligence

A branch of computing that builds systems able to perform tasks associated with human intelligence, including pattern recognition, decision-making and natural language processing.

Syntax Error

A violation of the grammar rules of a programming language, such as a missing semicolon or unmatched brace. The compiler reports it before the program can run.

Trace Table

A table used during a dry run that lists each step of a program alongside the current values of its variables, helping locate logic errors in loops and conditions.