Hosting jQuery on a Content Delivery Network (CDN) improves availability and performance at a reduced cost and with less network traffic, improves latency (the time it takes to send and receive a data packet from the server), and provides a device-specific version of the contents.

CDNs are a great way to host your JavaScript and CSS files. By caching these files, you can reduce the amount of time it takes for your site to load, making it faster and more responsive. This is especially important for sites that serve large amounts of content, such as blogs or e-commerce sites. By using a CDN, you can also reduce the number of load times that occur when visitors access your site. In addition, by hosting your JavaScript and CSS files on a CDN, you can also reduce the amount of bandwidth that is consumed by your site.

Example - It makes it simple to maintain responsiveness for mobile screen sizes, as well as safe storage space for important data or files. 

Caching JavaScript and CSS files on a CDN is an important optimization that should be considered when building a site with a lot of JavaScript and CSS files.