A landing page is where your visitor enters your site and a sales page is where you offer to sell them something and they make the choice to buy or not.
The two aren’t necessarily the same thing, although they can be.
It depends on what you are promoting, and whether your potential visitors are likely to be offended with a gentle sales message as soon as they get to your website and so on.
The Sales Funnel:
The idea with the sales funnel is to guide your visitors through your site to eventually land on a related sales page where you can try to persuade them to buy your product or service. The question need to ask is “what does my visitors really want?.
How do you get them to do this? This is the main question you need to answer and the main way to answer this question is to think about what the visitor wants.
If they have done a search on Google about a subject related to your product, take them to the page with little sales copy explaining why they should hire you a buy button and a phone no. so they can get in touch. Sometimes a nice article on some basic things a free video showing in exchange of their mail id (building a prospect list) enabling you to follow up with them via email, increasing your chances of getting a client and making a sale.