Multilingual site and domain(s). How right?

Question

Search Engine Optimization

Good afternoon. When developing a multilingual site, these three approaches are usually followed:
1. One language - one domain:
mysite.ru
mysite.com
mysite.cn
2. One language - one subdomain (on one domain):
ru.mysite.com
en.mysite.com
cn.mysite.com
3. One language - one site subsection (on one domain):
mysite.com/ru/catalog
mysite.com/en/catalog mysite.com/cn/catalog
Please explain the
pros and cons of all approaches. Thank you.

Answer 1

2 or 3
for SEO with competent linking, both are equivalent (there is also an option with country domains)
it’s more a matter of internal support and administration, (3) a little easier

Answer 2

Depends on the planned size of the site and the company for which it is made. The first option is good only for large international corporations. The second is for sites that plan to have several hundred pages in each language. The third is for small business card sites.