Extensions – also known as { -brand-name-firefox } Add-ons – are extra features you can download and install to add more functionality and tools to your browser. Add-ons allow you to customize your { -brand-name-firefox } browser and enhance the way you use the web.
Mae Estyniadau – sydd hefyd yn cael eu galw'n Ychwanegion { -brand-name-firefox }  – yn nodweddion ychwanegol y gallwch eu llwytho i lawr a’u gosod i ychwanegu mwy o ymarferoldeb ac offer i’ch porwr. Mae ychwanegion yn eich galluogi i addasu eich porwr { -brand-name-firefox } a gwella'r ffordd rydych yn defnyddio'r we.