A landing page is a standalone web page with a single purpose: getting the visitor to take one specific action. Sign up. Buy. Book a demo. Download a guide. That's it. Everything on the page exists to support that one goal.
This is fundamentally different from a homepage, which serves multiple audiences and goals simultaneously. A homepage is a lobby. A landing page is a sales meeting. The focused nature is what makes landing pages convert 2-5x better than general website pages for specific campaigns.
When you need a landing page
Paid ads: Always send paid traffic to a landing page, never your homepage. The landing page should match the ad's promise exactly (message match). This improves both conversion rate and Google Ads Quality Score.
Email campaigns: Each campaign with a specific offer should have its own landing page. "Learn about our new feature" shouldn't land on the generic features page — it should land on a page about that specific feature with a specific CTA.
Product launches: A dedicated page for the launch, not just a blog post. The page should build anticipation, explain the value, and capture signups or preorders.
The most important principle: one page, one goal. If your page tries to get visitors to sign up AND read your blog AND follow you on Twitter AND check out your pricing — it's not a landing page. It's a homepage pretending to be one.