Hello Student,

A single domain means a database for multiple domains is on a single website. Multiple domains means database are on separate domains.

A single domain encourages the giving of multiple products and services on a single website and avoids confusion. It makes the buying of products easier. However, it will be not able to deal with growth in several accounts.

While dealing with multiple customers or markets, multiple domains will be helpful. It encourages Search Engine Optimization or SEO which ensures that the link of your website will be chosen most number of the time. It requires proper attention to different databases and can be tiresome to maintain.

I hope it helps.

Thank you.