I observed some sites like Tech Crunch and their Image URL is showing up as techcrunch11.files.wordpress.com/xyz If there is a way to upload images to Wordpress server, then my websites server load will reduce. Do you have any idea what is it? I couldn't find it on Google. I get redirected to wordpress.com when I try to access files.wordpress.com
CDN / front-end caching: all scripts and stylesheets are served from our CDN. Images are served from our dedicated *.files.wordpress.com domain.
That page should answer your question regarding the WordPress.com CDN. cybmeta correctly stated that it is for VIP WordPress members only.