When an airplane comes down on the ground it is called landing
Similarly, when we click on any link a new page opens, it is called landing page.

In the realm of marketing, a landing page is a follow up to any promises that you’ve made in your content. Basically, it is a step your visitor takes towards becoming your client. Your landing page lets you make a trade, some sort of special offer, piece of information or a deal, in return for providing contact information.

Proper definition of landing page:
In online marketing, a landing page, sometimes known as a “lead capture page” is a single web page that appears in response to clicking on a search engine optimized search result, marketing promotion, marketing email or an online advertisement. The landing page will usually display directed sales copy that is a logical extension of the advertisement, search result or link.

Sales page

When your sibling asks you to bring a glass of water, your only purpose that moment is to persuade your sibling to get it on their own.
Similarly, the web page which has only one purpose that is to make the visitor purchase your product is called a sales page.

In technical words, a sales page is a single page on your website devoted to a single product. While it’s not strictly a landing page, it fits the criteria because it’s designed for a single purpose: to convert prospects.

“Landing page and sales page are the lungs and blood of your site”
Better the pages
Better is the revenue,
That is it.

Similarity and difference:

Landing page and sales page are both focused on a singular goal.
A landing page, though, doesn’t have to involve a sale.
A sales page is only for selling.
You might create a landing page to get people to sign up for your email newsletter or register for your webinar.

A good landing page is focused on a particular stream of traffic generated from an email campaign that’s promoting the Product.
Because the landing page is targeting just people who are (presumably) interested in this Product,
And because this Product is most desired by the ones coming through the link, you can convert a higher percentage of your website visitors into leads whom you can then follow up with.
Also, it is easy to create if you have all the knowledge to build one. If not then you Arystons is at your service providing you with satisfactory experience.

Whereas, the most difficult page to design is usually the sales page.
It’s one you would use at the very bottom of the funnel to persuade customers to purchase, which is a completely different proposition than a simple info taker and info provider.
It is the most delicate and requires the right strategy and knowledge to build it.
If you can create on your own, well and good; if not then you know we are there to help you.