What Is React? A Plain Guide — Web Design, SEO and Frameworks

What Is React? In the Simplest Terms

When people say "website," they usually picture menus, buttons, photos and forms. React works exactly at that layer — the interface users see and interact with.

In the traditional approach, a page behaves like one big HTML file. React splits it into components. Each component is independent; updating a card does not redraw the entire page.

React is a library, not a full framework. It focuses on building interfaces; Next.js fills the routing, server and SEO gaps.

Basic JavaScript is required first: variables, functions, arrays and objects. JSX and hooks sit on that foundation — a sensible path is JS, then React.

What Is React Used For?

• Corporate websites — multilingual, SEO-ready platforms with Next.js
• E-commerce storefronts — filters, cart, dynamic product cards
• Admin panels and dashboards — dense data, tables, charts
• Single-page applications (SPA) — smooth transitions without full reloads
• Mobile apps — iOS and Android via React Native
• SaaS products — subscriptions, settings, live data

Netflix, Instagram, WhatsApp Web, Airbnb and Uber actively use React or React-based UI stacks.

How Does React Work? In 5 Steps

1. Define a component — write UI in JSX (a button, card, etc.).
2. Build a virtual tree — React keeps a lightweight copy of the DOM in memory.
3. State changes — user clicks or types; internal component data updates.
4. Compute the diff — old and new virtual trees are compared.
5. Update the DOM — only changed nodes are repainted; the page stays smooth.

Virtual DOM: React's Hidden Superpower

One reason React feels fast is the Virtual DOM. Complex term; simple explanation:

1. When a user clicks a button, React applies the change in virtual memory first.
2. It compares the old view with the new one (diffing).
3. It updates only the changed slice on the real page — not the whole document.

This logic was born to solve Facebook's ad dashboard performance bottleneck; today it is a core reason modern sites feel fast.

What Is JSX?

JSX (JavaScript XML) lets you write HTML-like markup inside React components. Browsers do not understand JSX directly — build tools like Babel compile it to standard JavaScript.

function Hello() {
  return <h1>Hello, React!</h1>;
}

Example 1 · Minimal JSX component

function Card({ title, description }) {
  return (
    <article>
      <h2>{title}</h2>
      <p>{description}</p>
    </article>
  );
}

function App() {
  return <Card title="What Is React?" description="UI library" />;
}

Example 2 · Passing props

See the official react.dev JSX guide for deeper learning.

React Hooks: useState and useEffect

Hooks let functional components manage state and side effects — standard since React 16.8.

useState — hold data inside a component

import { useState } from 'react';

function Counter() {
  const [count, setCount] = useState(0);

  return (
    <button onClick={() => setCount(count + 1)}>
      Clicked: {count} times
    </button>
  );
}

Example 3 · Counter with useState

useEffect — side effects

import { useEffect, useState } from 'react';

function UserProfile({ id }) {
  const [data, setData] = useState(null);

  useEffect(() => {
    fetch(`/api/user/${id}`)
      .then((r) => r.json())
      .then(setData);
  }, [id]);

  return data ? <p>{data.name}</p> : <p>Loading...</p>;
}

Example 4 · Fetch with useEffect

Props vs State

Short rule: props come from outside, state is managed inside.

Criteria	Props	State
Source	Parent component	The component itself
Mutable?	No — read-only	Yes — via setter
Example	<Card title="..." />	useState(0)
Purpose	Data passing	Interactive, changing UI

React vs Vue vs Angular

Feature	React	Vue.js	Angular
Type	UI library	Progressive framework	Full framework
Learning curve	Medium	Easy–medium	Hard
Performance	High (Virtual DOM)	High	Medium–high
SEO (modern stack)	Very strong with Next.js	Strong with Nuxt	SSR built-in
Job market	Largest	Growing	Enterprise-heavy
Maintained by	Meta	Community + Evan You	Google

For corporate web and SEO, Hitit Medya standardises on React + Next.js for proven performance and long-term maintainability.

How Did React Come About?

From WordPress to Next.js

For much of the 2010s the web revolved around WordPress. As mobile traffic grew and Google made speed a ranking signal, limits became clear. Community momentum shifted toward React and Next.js. State of JS surveys show React as the most used frontend library for years; npm weekly downloads exceed 20 million.

See our web design agency selection guide for the engineering side of this shift.

Why Is React Good for SEO?

React at Hitit Medya: Proof and Measurement

Our Engineering Team: Four Software Engineers, ISTUN and React

Hitit Medya's software core is built on a strategic partnership of four senior software engineers who graduated from the Software Engineering programme at Istanbul Technology and Health University (ISTUN). We do not outsource architecture — engineering decisions, code quality and performance measurement sit with the team that writes the code.

At ISTUN, React was not a single lecture topic but central to the curriculum. Modern interface development was taught on a JavaScript foundation: component thinking, state management and real project delivery. React is therefore not a trend we picked up later — it is a production standard internalised through university discipline.

After university we extended this line with the Next.js App Router, TypeScript and production environments. Meta Open Source CLA participation and live PageSpeed measurements show the ISTUN React focus continuing in the field.

See profiles, GitHub contributions and signature projects on our Team page.

Today the team uses React systematically in these areas:

• Web: Corporate sites, e-commerce and multilingual platforms with React + Next.js
• Mobile: iOS and Android from one codebase via React Native
• Performance: Virtual DOM, code splitting and lazy loading by design
• Maintenance: Component structure keeps long-term update costs low

Popular React Frameworks

For Business Owners

References

Frequently Asked Questions

01Is React a framework or a library?

React is a library focused on the UI layer. Routing, data fetching and SEO typically come from frameworks like Next.js.

02What is JSX?

JSX is syntax that lets you write HTML-like markup in JavaScript. It is compiled to standard JavaScript at build time.

03What is the difference between props and state?

Props are passed from a parent and are read-only. State is internal data that updates with user interaction.

04Do I need JavaScript before React?

Yes. Variables, functions, arrays/objects and basic DOM knowledge make learning React much easier.

05React vs React Native?

React is for web UI. React Native uses the same component model for iOS and Android apps.

06What is the difference between React and WordPress?

WordPress offers a fast start with themes and plugins; React builds a custom interface. For corporate, fast, SEO-focused projects, React + Next.js is usually a stronger foundation.

07What is the Virtual DOM?

The Virtual DOM is React applying changes in memory first and updating only the diff on the real page — the mechanism that solved Facebook's dashboard performance problem.

08Is React good for SEO?

With modern frameworks like Next.js, yes. Server-side rendering and static generation mean Googlebot sees ready HTML. Hitit Medya targets 90+ PageSpeed on every project.

09How long does it take to learn React?

With basic JavaScript, 2–4 weeks of practice covers JSX, components and hooks. Production-level Next.js work usually needs months of project experience.

10What does Hitit Medya use?

Next.js App Router, React, TypeScript, Tailwind CSS. Details: React Web Design.