A landing page is a web page built for one purpose, usually to get a visitor to take a single action such as signing up, joining a waitlist or starting a trial.
For a startup it's often the home page: a headline that says what the product does, a screenshot, proof, pricing and one call to action.
Separate landing pages are also made for campaigns, audiences or search terms, each speaking to one kind of visitor.
Why it matters for a launch
Every launch, directory listing and post sends people to a landing page. If it doesn't explain the product in seconds, the traffic is wasted.
Read more: How to write a SaaS landing page