Cross-browser vs. Multi-browser

 Cross-browser

Cross-browser refers to the ability of a website, web application, HTML construct  

or client-side script to function in environments that provide its required features and to bow out or degrade gracefully when features are absent or lacking.

 Cross-browser vs. Multi-browser

With regard to scripts, which is the most common usage, the term cross-browser is often confused with multi-browser (see jQuery). Multi-browser scripts can only be expected to work in environments where they have been demonstrated to work (due to assumptions based on observing a subset of browsers). Most publicly available libraries and frameworks are multi-browser scripts and list the environments (typically popular browsers in use at the time and in their default configurations) where they can be expected to work.