Systems Design

An API is a communication bridge between the frontend and the backend.

Backend is the brain and engine of a website or application. Users usually don't see it, but it does all the important work in the background.

Cache is a shortcut copy of data stored temporarily so it can be retrieved quickly instead of being recreated or fetched again.

A database is a digital storage system that keeps information organized so it can be found and managed quickly.

Frontend is the visible and interactive part of a website or app.

HTML builds the house, CSS paints and decorates it, while Sass and BEM keep everything organized, and Responsive Design makes it fit every screen.

Java is a powerful backend language built to run large, reliable applications on almost any computer.

JavaScript is the "brain" of a website that reacts to what users do.

Next.js is React with built-in tools for creating fast, SEO-friendly, production-ready websites.

PHP is the server's worker that builds the webpage before sending it to your browser.

Python is the worker behind the website that receives requests, does the work, and sends back results.

React Native lets you build Android and iPhone apps using one React codebase instead of two separate ones.

React is like building a website using reusable LEGO blocks that automatically update when the data changes.

RegEx is a smart text filter that finds or checks words based on a pattern instead of reading every character yourself.

An SDK is like a toolbox that gives developers everything needed to build apps for a specific service.

A system that remembers who you are and what you did in your previous steps, keeping that memory active as you continue interacting with it.

A system that has no memory of the past. Every time you talk to it, it is like meeting a stranger for the first time, so you must explain everything they need to know in that single request.

Storage is the digital cupboard or warehouse where a computer keeps files safely for future use.

A digital security pass or ticket that proves you are allowed access, without having to enter your username and password every time.

DNS TTL is an expiry timer attached to a DNS record. Until the timer expires, devices can reuse the saved answer instead of asking the DNS server again.

TypeScript is JavaScript with a spell-checker that finds coding mistakes before your website runs.