Subdomain hosted on a different server VS Subfolder on main server

[vermont]

We have a website developed in ColdFusion on a server does not support PHP. We have a blog for the site using WordPress (PHP), hosted on a different server, with a subdomain as the URL. (example: blog.website.com)

I've heard that search engines treat subdomains as completely different websites from the main domain, so they could actually be in competition for rankings in the search engines - is that correct?

I am under the impression that the traffic to the blog will not show as traffic to the main website, because it is hosted on a different server - is that right?

If I am correct, I assume the best solution would be to install PHP on our main server, and put the blog in a subfolder ... or would the subdomain be OK as long as the blog is hosted on the main server?

Thanks!

[NakulGoyal]

A sub-folder would be best. So if you can install PHP, that would be great. If not, or if there are security concerns, I would suggest looking into Reverse Proxy.