"Pound" is the American equivalent of "hash" - they both refer to the "#" key.
The default language of your browser or computer isn't British English. In a browser, you can change the display language to British English.
On a Mac, you can change the default language to English (UK) by:
- Opening the Apple menu
- Select System Preferences
- Choose 'Language & Region'
- Click '+' at the bottom of the dialog box
- Select 'English (UK)' and press 'Add'
- Drag and drop the language you want to use as default to the top of the list