A landing page is a is a single web page that has been created specifically for an advertising or marketing campaign. Ads on Facebook, Google, Twitter, Instagram etc typically perform better, with stronger conversions when visitors are taken to a landing page that exactly matches the ad that they clicked.
Unlike web pages which have many goals, and encourage visitors to explore the site, a landing page has a singular focus, with a single call to action.
Once you have managed to attract visitors to your offer, the last thing you want are distractions that will diminish the likelihood of a conversion. Landing pages have a single goal, be it generating a lead, capturing an email address or convincing somebody to buy.
Landing pages can be rapidly deployed with dedicated landing page software such as Unbounce or Instapage. This makes them ideal when you have to get to market quickly. Typically a landing page can be designed and deployed in as little as 24 hours.
Google Ads and landing pages are perfect together. Google determines how much you pay per click based on ad copy and landing page experience, the ability to test and iterate your page quickly results in a lower cost per acquisition.