So I came across a library that helps with adding locale code to the route of your website. eg website.com/en-US/about/
The library claims that one should do it this way because "Google needs different URLs to crawl and render your pages for each language.". Is this correct?
Also, would simply putting the locale code in the query string accomplish the same thing? eg website.com/about/?locale=en-US
More generally: what are the advantages and disadvantages of route-based vs query-based?