Maharashtra HSC IT Commerce flashcards

32 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. Information is data that has been processed, organised and given context so it becomes meaningful for decision-making.

IPOS cycle

Input, Process, Output, Storage: the four stages describing how a computer system accepts data, manipulates it, presents results and retains data for later use.

RAM and ROM

RAM is volatile read/write memory holding running programs and is lost on power off. ROM is non-volatile, mainly read-only memory storing firmware such as the BIOS.

Hexadecimal number system

A base-16 number system using digits 0–9 and letters A–F, where A equals 10 and F equals 15. It compactly represents binary, since one hex digit equals four bits.

Open source software

Software distributed with its source code available, allowing anyone to study, modify and redistribute it under a licence, for example Linux or LibreOffice.

Functions of an operating system

Process management, memory management, file management, device management, security and user-interface provision. The OS coordinates hardware and software resources for application programs.

Time-sharing operating system

A multitasking OS that allocates each user or process a short CPU time slice in rotation, giving many interactive users the impression of simultaneous, dedicated use.

GUI versus CLI

A GUI uses windows, icons and menus manipulated by mouse for ease of learning. A CLI accepts typed commands, offering speed, scripting and lower resource use.

Booting process

Startup sequence where POST checks hardware, the bootloader locates and loads the OS kernel into RAM, and the kernel initialises drivers and services.

HTML document structure

A page begins with <!DOCTYPE html>, then <html> containing <head> for metadata and title, and <body> for visible content. Void tags like <br> need no closing tag.

CSS box model

Every element is a box with content at the centre, surrounded by padding, then border, then margin. Width and height normally apply to the content area only.

Class versus id selector

A class selector (.name) may be reused on many elements; an id selector (#name) must be unique per page. Id selectors carry higher CSS specificity than classes.

External style sheet

A separate .css file linked in the HTML head using <link rel="stylesheet" href="style.css">, letting one style definition apply consistently across many pages.

IoT architecture layers

Four layers: perception (sensors and actuators), network (connectivity such as Wi-Fi or 5G), middleware (data processing and storage) and application (user-facing services).

Cloud service models

IaaS provides virtual machines and storage; PaaS provides a managed development and runtime platform; SaaS provides ready-to-use applications over the internet, such as webmail.

Supervised versus unsupervised learning

Supervised learning trains on labelled data to predict outputs, as in classification and regression. Unsupervised learning finds patterns in unlabelled data, as in clustering.

5G key characteristics

Fifth-generation mobile networks offer peak rates near 20 Gbps, latency around one millisecond and very high device density, supporting eMBB, URLLC and massive machine communication.

Narrow AI

Artificial intelligence designed for one specific task, such as voice assistants, recommendation engines or image recognition. All widely deployed AI systems today are narrow AI.

let versus var

let declares block-scoped variables that cannot be accessed outside their enclosing block. var is function-scoped and hoisted, which can cause unexpected values before declaration.

Arrow function

Compact JavaScript syntax written as (params) => expression. It inherits this from the enclosing scope instead of binding its own, unlike a regular function expression.

Event bubbling

After an event fires on a target element, it propagates upward through its ancestors, allowing a parent handler to respond to child events; stopPropagation halts this.

Array map method

map() calls a callback on every array element and returns a new array of the results, leaving the original array unchanged. It is used for transforming data.

Promise states

A promise begins pending, then settles as fulfilled with a value or rejected with a reason. Handlers attached with then and catch run once settled.

PHP superglobals

Built-in arrays available in every scope: $_GET and $_POST hold form data, $_SESSION stores per-user server data, $_COOKIE holds cookies, and $_SERVER holds server information.

PHP session handling

Calling session_start() creates or resumes a session identified by a cookie, storing user data in $_SESSION on the server. session_destroy() ends it.

SQL injection prevention

Use prepared statements with bound parameters so user input is treated as data, not executable SQL. Also validate input and avoid building queries by string concatenation.

Primary key

A column or column set that uniquely identifies each row in a table. It must be unique and cannot contain NULL values; each table allows only one primary key.

WHERE versus HAVING

WHERE filters individual rows before grouping occurs. HAVING filters groups after GROUP BY and is typically used with aggregate functions such as COUNT or SUM.

Third normal form

A table is in 3NF when it is in 2NF and has no transitive dependency, meaning non-key attributes depend only on the primary key, not on other non-key attributes.

E-commerce models

B2B: business sells to business. B2C: business sells directly to consumers. C2C: consumers trade through a marketplace platform. Each differs in scale and payment handling.

CIA triad

Confidentiality ensures only authorised parties access data; Integrity ensures data is accurate and unaltered; Availability ensures systems and data are accessible when required.

Phishing

A social-engineering attack using fraudulent emails, messages or fake websites that impersonate trusted entities to trick users into revealing passwords, OTPs or card details.