# A Glossary of Common Terms

:::{topic} Content
Usually refers to webpages being rendered, may also be seen as "running in
content" in which case it can include UI privileged code running in a process
that is rendering webpages.
:::

:::{topic} Chrome
Usually the parts of the application UI outside of the rendered webpage
:::

:::{topic} XUL
A proprietary UI definition language that we are slowly phasing out and replacing with standard HTML.
:::

:::{topic} l10n
An abbreviation for Localization.
:::

:::{topic} i18n
An abbreviation for Internationalisation
:::

:::{topic} a11y
An abbreviation for Accessibility
:::