Beginner 12 min read

What Is Lightning Web Components?

By the end of this lesson, you'll be able to:

  • Explain what Lightning Web Components (LWC) is and the problem it solves
  • Describe how LWC relates to the broader Salesforce Lightning platform
  • Identify the core technology LWC is built on

Prerequisites: None — this is the first lesson of the course.

What Problem Does LWC Solve?

Salesforce orgs constantly need custom user interfaces beyond what point-and-click tools (Page Layouts, Flow) provide — dashboards, wizards, dynamic search, anything with real interactivity. Before Lightning Web Components existed, this meant Visualforce (an older, server-rendered page technology) or Aura Components (Salesforce's first component framework, built on its own proprietary programming model).

LWC is Salesforce's newer answer to this need: build custom UI using real web standards, running fast, natively in the browser — not a Salesforce-only dialect you'll never use anywhere else.

Built on Web Standards, Not a Proprietary Framework

Aura invented its own component syntax and lifecycle from scratch. LWC instead is built directly on Web Components — a set of browser-native APIs (Custom Elements, Shadow DOM, HTML Templates, ES Modules) that every modern browser supports out of the box, with no framework required underneath.

This is the single most important thing to understand about LWC: the JavaScript, HTML, and CSS skills you build in this course are real web development skills, not a proprietary dialect that only works inside Salesforce. Module 4 covers exactly which parts of modern JavaScript you need, all with LWC-specific examples.

Why This Matters in Real Salesforce Projects

  • Performance — LWC compiles down to near-native browser code, and generally runs noticeably faster than the equivalent Aura component.
  • Hiring and onboarding — any developer who already knows modern JavaScript has a genuine head start on LWC, unlike Aura's Salesforce-only syntax.
  • Platform direction — Salesforce's own Lightning Experience and the Salesforce Mobile App are now built largely on LWC internally. When the platform vendor invests its own product in a technology, that's a strong signal for where new development should go.
  • Today, the large majority of new custom UI work on Salesforce defaults to LWC, with Aura reserved for legacy maintenance.

How LWC Fits into the Salesforce Platform

A single LWC component can be placed on Lightning App Builder pages (Home, Record, App pages), used inside Lightning Experience, exposed in the Salesforce Mobile App, and embedded in Experience Cloud sites (Salesforce's customer/partner portal product) — all from one codebase. Lesson 4 covers every one of these surfaces in detail.

Exercise

As a comment, write 2-3 sentences explaining to a teammate who has only used Visualforce why LWC is now Salesforce's recommended approach for new custom UI development.

Show hint

Focus on web standards vs. proprietary technology, and performance.

JAVASCRIPT

Exercise

Challenge: list three concrete scenarios in a Salesforce org where you would build a custom LWC rather than rely on a standard Lightning App Builder component or a Flow.

Show hint

Think about interactivity, custom visualizations, and data views no standard component provides.

JAVASCRIPT

What Is Lightning Web Components? Quiz

1. What is LWC primarily built on?

2. Which of these is a genuine advantage of LWC over Aura Components?

3. LWC completely replaced Aura Components overnight, and no orgs use Aura anymore.

4. Where can an LWC be used within the Salesforce ecosystem?

5. A developer says: "I'll build this in Aura since that's what the last few developers on this project used." Is this good default reasoning for a brand-new component today?

6. Because LWC is built on web standards, skills like DOM structure, ES6 JavaScript, and CSS learned outside Salesforce transfer directly to LWC development.

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Summary

LWC is Salesforce's modern UI framework, built on native web standards rather than a proprietary abstraction — the same HTML/JavaScript skills used across the web transfer directly.