Firefox – Keyboard shortcut to quickly jump to the URL address field in Firefox

In Firefox I very often want to quickly enter a new URL in the address field. Therefore it would be very nice to be able to quickly jump to the URL address field with a keyboard shortcut! Today I must move my mouse and place the cursor in that field and also ensure that the current address is selected so I can overwrite it when entering the new URL. Very annoying!

I'm sure I'm not the first one to have this need so there is probably a shortcut or an extension that does this already, but I cannot find that information!