Wordpress as a separate domain or install under a subfolder?
I have a news website. However I started it not in wordpress, but built it myself from the ground up. For now I do not want to transfer it to wordpress. But I also want it to have a separate page just dedicated to a wordpress blog. can you install wordpress to a subfolder of a website/domain name so the blog main url will read like: mynewswebsite/wpblog.php? and then run the wordpress just the same as if it is running as a regular website? Or even if it is possible there would be complicating issues?
And first of all, does this make sense? I am asking this because I thought about starting a wp site with a totally separate domain, but the subject matter is the same, so it is like dividing the same subject content and that would not be good for SEO am I wrong?