There are many marketing terms that revolve around performance. Some of those performance marketing term definitions are:
Browser caching - a tool that speeds up your website by storing frequently used content in local memory
Minimal page redirects - sending a page through many redirects not only makes your site suspicious to search engines but it also slows down the performance of a website
Image size - the size (in kb or mb) of an image. Large images slow down your website's load time. As a general rule of thumb, images should be no larger than 400kb.
Minified Javascript or CSS - The removal of all unnecessary characters in code without changing the site functionality. This results in a more compact and easy file to load and crawl by search engines.