Difference between /var/www/html directory and /www as root directory

I was setting up a website on a web hosting service.

When I was transferring the files using ssh, I had to put the files in the www folder in my root directory (I would use cd www to get there), but when I was using AWS server in the previous occasion, I had to go to /var/www/html directory to put the files in and get the website running.

Are there any differences to these two formats? The website works fine, but I was just worried that there may be a pitfall or something!

Thanks in advance!