I/O | Tech Stack

Question 1

Programmed I/O

Answer 1

Programmed I/O is a basic method of transferring data between the CPU and I/O devices (like keyboards, printers, or hard drives), where the CPU manages everything manually.

The CPU runs instructions to check if a device is ready.

It waits in a loop (called polling) until the device says: “I’m ready!”

Then it performs the data transfer.

🧍‍♂️ It’s like standing in line at the printer, constantly asking, “Are you ready now?”

Question 2

Interrupt Initiated I/O

Answer 2

Interrupt-Initiated I/O is a smarter way for the CPU to handle input/output operations. Instead of constantly checking (polling) an I/O device to see if it’s ready (like in Programmed I/O), the device simply notifies the CPU when it’s ready by sending an interrupt signal.

This means the CPU can:

Work on other tasks,

And only stop to handle I/O when necessary.

💡 “Don’t call us — we’ll call you when we’re ready.”

Question 3

Technology Stack

Answer 3

Set of technologies used to build an application. refers to the combination of software
products, programming languages, and tools used to develop and operate a software
application or service.

Question 4

Front-end

Answer 4

The part of the program that interfaces with the user

Question 5

Front End Languages

Answer 5

HTML, CSS, JavaScript, ReactJS, TypeScript, Elm, Swift

Question 6

Frameworks

Answer 6

React, Angular, Vue.js, Ember.js, Backbone.js, jQuery, Bootstrap

Question 7

Back-end

Answer 7

The part of the program that does the “behind-the-scenes” work. responsible for
managing the business logic of the application, handling data processing and storage, and
delivering information to the front-end for display to the user (server, application, and
database)
○ Languages: Python, Java, PHP, Ruby, C++/C/C#
○ Frameworks: Node.js, Ruby on Rails, Django, Spring
○ Databases: MySQL, MongoDB, CouchDB, Oracle
○ Databases, Programming languages, Frameworks, Web Servers
○ js=javascript and DB/SQL are databases

Question 8

LAMP stack (Linux-OS, Apache-server, MySQL-database, and PHP-programming
language)

Answer 8

■ For hosting web pages on a Linux machine
■ Used to build websites and web applications
■ All 4 components are free and open-sourced
■ Backend stack

Question 9

WAMP stack (Windows, Apache, MySQL, and PHP)

Answer 9

■ Only difference between LAMP is the operating systems (Linux vs. Windows)
■ Backend stack

Question 10

MEAN stack (MongoDB, Express.js, AngularJS, and Node.js)

Answer 10

■ For building dynamic web apps
■ Open-source end-to-end JavaScript stack largely used for cloud-hosted
applications (very flexible and scalable)
■ Full stack

Question 11

MEVN stack (MongoDB, Express.js, VueJS, Node.js)

Answer 11

■ Full stack
■ MEVN is more like MEAN than MERN

Question 12

MERN stack (MongoDB, Express.js, React, and Node.js)

Answer 12

■ Enables the development of full-stack JavaScript applications.
■ Full stack

Question 13

Web application framework

Answer 13

software framework designed to support the
development of web applications. Provide a standard way to build and deploy web applications. Aim to automate the overhead associated with common activities
performed in web development.

Question 14

ASP.NET

Answer 14

open-source web framework, created by Microsoft, for building modern web
apps and services that run on macOS, Linux, Windows, and Docker.

Question 15

Ruby on Rails

Answer 15

a full stack framework

Question 16

Hadoop

Answer 16

Apache Hadoop is a Java-based, open-source framework that lets you store and process huge amounts of data using a cluster of computers — often called nodes.

It’s built to handle Big Data, meaning:

Massive volumes of data (terabytes or petabytes),

From many sources,

Needing fast and reliable processing.

🗂️ Think of Hadoop as a giant warehouse system that breaks up data, stores it across many machines, and processes it in parallel.

Question 17

MongoDB

Answer 17

MongoDB is a popular NoSQL database that stores data in a document-oriented format instead of traditional rows and columns like in SQL databases.

It’s open source

It’s built for high performance, flexibility, and scalability

Data is stored as documents in a format called BSON (Binary JSON)

💡 Think of MongoDB as a giant digital filing cabinet full of smart folders (documents) instead of spreadsheets.

Question 18

CouchDB

Answer 18

CouchDB is an open-source NoSQL database that stores data in JSON documents and is designed for:

Ease of use

Reliable replication

Offline-first and distributed environments

Its killer feature is built-in syncing and conflict resolution — perfect for mobile apps and systems where data is collected and updated on many devices.

💡 Think of CouchDB like a self-syncing notebook that can merge updates from many people — even when they’ve been working offline.