A landing page in Google Analytics is the first page a user views in a session. This could be your blog post, a product page, a lead capture page, and so on. Basically, a landing page is where a user first arrives when they click a link that lands on your website.
Conversions are the end goal of your landing pages, and they vary based on your website and business. For instance, if you’re a publisher, a conversion could be getting people to sign up for your newsletter or download your ebook. Similarly, if you’re running an eCommerce store, a conversion would be when a visitor makes a purchase.