Multiple sites on the same domain - Good or bad?

1. Is it a good idea to have multiple websites?
2. Can one domain have multiple websites?
3. What happens if two websites have the same domain?
4. Is having multiple websites good for SEO?

Is it a good idea to have multiple websites?

It's still not a great idea to have multiple sites because they will compete with each other to rank in the search engine results pages (SERPS). Unless your sites are for very distinct business lines or products, odds are that you'll be using the same or very similar keywords across both websites.

Can one domain have multiple websites?

One domain can be mapped to only one website at any given time. But different domains can point to the same website. If you buy a domain name of your own, you can add any number of subdomains you want, and have them point to different websites.

What happens if two websites have the same domain?

Two websites can't have the same name because registrars only allow one owner per domain name. If someone has already registered example.com , nobody else can use it until it is abandoned by its owner. Thanks! You answered my question.

Is having multiple websites good for SEO?

You Run the Risk of Duplicate Content

Much like trying to rank for the same keywords across different sites, duplicate content can nullify your SEO progress. Essentially, when a search engine finds multiple pieces of the same content, it won't know which is the original piece to rank.