What is referral in GA?
 

What is meant by referral traffic in Google Analytics?
Is it good for our website or not?

Referral traffic increases the "page rank" of your websiste and blog, which boosts it in Google search results. High rankings in Google are coveted, as being listed on the first page of a search can lead to many more clicks than if your site showed up on the fourth or fifth page of search results. Referral traffic is also important because it provides a steady source of traffic outside of search engine hits.

Yes Its Good for our website

My referral host names are ends with ____ .ml, ____.xyz etc. like this.
Is this type of referral is good for website?

yes it is good it increases the "page rank" of your website and blog, which boosts it in Google search results.