Is it SEO-friendly to redirect with .htacces to the same PHP file?

Question

Suppose I have a .htaccess file, which would take a SEO-friendly URLs like www.site.com/sub-category/spices, www.site.com/sub-category/vegetables etc, and redirect them to the file www.site.com/sub-category/page_generator.php?item=spices. That is, page_generator.php would take the last part of the URL as a GET parameter, and then generate the page with database calls.

I do not know a lot a about search engines, but I think that a search engine cannot see page_generator.php (since it's hidden by .htaccess), and thus associates the resulting webpage with the URL www.site.com/sub-category/spices, and not www.site.com/sub-category/page_generator.php?item=spices, which is good in terms of SEO.

Is this correct?

Answer 1

Is this correct?

Basically, yes.

redirect them to the file...

It's more usual to refer to this as a URL rewrite (or internal rewrite), rather than a "redirect" - which is more commonly used to refer to an (external) HTTP redirect. Although it is still a redirect of sorts and the Apache docs do often refer to it as an "internal redirect".

which is good in terms of SEO.

Strictly speaking, these are "user"-friendly URLs, not necessarily SEO-friendly. Search engines understand the URL parameters perfectly well - so to the search engines it makes little difference. However, users find them easier to deal with, which can improve click-through rates. So, indirectly, they can help draw traffic to your site, but they do nothing to improve your ranking directly.