📝 Summary

This article compares Lightning Web Components (LWC) and Aura Components, the two main component models in Salesforce’s Lightning platform. It explains their architecture, use cases, and best practices to help developers choose the right approach for building modern Salesforce applications.

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⚙️ What Are Lightning Components?

Salesforce Lightning offers two component models:

Component Model	Introduced	Description
Aura Components	2014	Original component-based framework built by Salesforce
Lightning Web Components (LWC)	2019	Modern web standards-based framework built on native browser APIs

🔍 Key Differences: LWC vs. Aura

Feature	Lightning Web Components (LWC)	Aura Components
Language	Modern JavaScript (ES6+), HTML, CSS	Aura Markup (XML-like), JavaScript (ES5)
Performance	Faster, lighter, optimized	Slower due to abstraction and older standards
Standards	Built on Web Components standard (native HTML APIs)	Salesforce proprietary model
Learning Curve	Easier for web developers familiar with JS frameworks	Requires learning Aura syntax
Tooling Support	Better support in VS Code, LWC Extensions	Limited support
Interoperability	Can work with Aura via lightning:container	Aura can host LWC inside
Shadow DOM	Uses Shadow DOM for encapsulation	No native Shadow DOM
Testing	Jest (unit testing), LWC Test Utils	Jasmine-based testing for Aura
Reusability	Higher due to standardization	Lower due to tight Salesforce dependency

🧪 When to Use Each

✅ Use LWC When:

• Building new components or apps.
• You need better performance and responsiveness.
• You prefer standard JavaScript development.
• You want to leverage modern web tools (e.g., VS Code, Jest).
• You aim to future-proof your development efforts.

✅ Use Aura When:

• Maintaining legacy Salesforce components.
• Working in areas not fully supported by LWC (e.g., certain App Builder customizations).
• You need deep integration with Aura-only services (though this is shrinking).

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🔄 Interoperability

• LWC inside Aura: You can embed LWC components inside Aura components using <c:myLwcComponent />.
• Aura inside LWC: Not directly supported. Requires a wrapper Aura component.

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🛠 Example Comparison

🔹 LWC Example (HelloWorld)

// helloWorld.js
import { LightningElement } from ‘lwc’;

export default class HelloWorld extends LightningElement {
greeting = ‘Hello, World!’;
}

<!– helloWorld.html –>

</template>

<p>{greeting}</p>

<template>

🔸 Aura Example (HelloWorld)

<!–helloWorld.cmp

<aura:component>

<aura:attribute name=”greeting” type=”String” default=”Hello, World!” />

<p>{greeting}</p>

</aura:component>

🔐 Security and Access Control

Aspect	LWC	Aura
Locker Service	Fully enforced	Fully enforced
Access Modifiers	Uses @api, @track, @wire	Uses aura:attribute, access="global"
Data Binding	One-way (reactive)	Two-way

🧭 Migration Strategy

If you’re currently using Aura Components and want to move to LWC:

1. Start with new features in LWC.
2. Embed LWC in Aura wrappers to incrementally migrate.
3. Refactor existing Aura logic gradually.
4. Use naming conventions and version control to track migration.

🏁 Summary Table

Criteria	LWC	Aura
Speed	✅ Faster	❌ Slower
Web Standards	✅ Yes	❌ No
Tooling	✅ VS Code, Jest	⚠️ Limited
Migration Recommended	✅ Yes	❌ Legacy Only