Showcase all your website content in a single page
This saves time for viewers because they don't need to skip from one page to another.
The loading-speed is optimised.
Furthermore, it makes user experience, especially on mobile devices, more continuous and fluid. In essence, this results in increased conversions without distraction.
It's easy to manage and less resource-centered to have one-page websites.
Answers to your questions
What does a one page website look like?
It is a website that does not have extra pages like About, Terms and Services sections, etc. It uses only one page of HTML. All the content fit in a single page that is in a long-scrolling style. It can be user-friendly and very intuitive as your visitors don't get lost in multiple layers of navigation. Every component is simplified and gets to the point.
When to use a one page website?
It can make sense for certain small-scale projects. For example:
Landing pages. No distractions and easy to focus on the most important information. For small businesses that sells one product.
Brochure website. You just need to introduce your services with contact information.
Portfolios. Freelancer that need to give some information about you
Is one page website good for SEO?
Good news! More content does not mean better ranking on Google.
A multi-page website will always be better for SEO but with some tricks, a one-page website can still rank well. Keywords will have to be searched more thoroughly and mapped in thematic groups. The H1 tag will have to be added to each section. Make sure that the page is not too heavy in order to increase the speed and the user experience.
Can I make money with a one page website?
Definitely! Just be very selective in your target market.
You can either use your website to attract leads to your physical store or sell your services and products online or use direct methods like:
Google Adsense that will serve contextual ads relevant to your website. You get paid for every click. (PPC Advertising network)
Value click that works like Google Adsense, but you get according to the number of impressions (ie.,pages views). (CPM Ad network)
Affiliate marketing when a merchant let other people sell directly or indirectly its products and services in exchange for a commission
One page website VS multiple page website
One-page offers fewer SEO opportunities, a limited content-length, and a single focus. However, it's the best option if you just need to highlight your information in a simple way and design.
Multi-page needs constant maintenance can be too distractive and much more complex for mobile users. But if you offer multiple products and/or services and want to have a strong authority online, that would be the best option.