Domain names are one of the factors used by the search engines that give websites a boost in search engine result pages.
If you want your domain to give some SEO benefits to your website, here are the top factors to consider:
The age of the domain carries weight in terms of SEO. The older the domain, the more authority is given to the website. So, if you have a number of competing websites with the same quality and quantity of content, then the site with the oldest domain will be given higher marks by the search engines.
If the domain contains a keyword that is part of the SEO efforts, then the website will also be given more authority. For example, if the business website is in the fashion industry, then having the word “fashion” as part of the domain will carry some SEO benefits.
The shorter the domain, the better. Maximum should be 2 words. Domains may be 3 words only if warranted such as “Real Estate” when the industry itself has 2 words.
Dotcom is by far the most important and popular extension used by virtually all major companies. It is the most respected both by the search engines and people in general. Domains in dot net, dot org, and few others can also be used and help SEO but don't carry the same weight as dot com.
You should avoid dashes. Domains with dashes not only confuse visitors but also are associated with spammy websites and generally poor websites