What Is a Landing Page?
In a nutshell, a landing page is any webpage on which an Internet visitor first arrives on their way to an important action that you want them to take on your site. The landing page can be part of your main website, or a stand-alone page designed specifically to receive traffic from an online marketing campaign.
Strictly speaking, it is not just the landing page that you should be optimizing, but rather the whole path from the landing page to important conversion actions (such as purchases, form-fills, or downloads) often happening somewhere deeper in your website.
So why pay so much attention to landing pages and important conversion paths instead of optimizing the whole website?
The famous 80/20 rule applies perfectly ...