(Sorry, I’ve lost rankes and corrected).
(technical, scientific) milliard = 1 000 000 000 (10**9)
In spoken language(s) it is also used as an equivalent for ‘billion’, which also can mean in some contexts 1012 (and in some contexts can be used as an equivalent for trillion = ? (…which, in turn, sometimes = 1018 )
‘The word “billion” and its equivalents in other languages refer to either one million million or one thousand million, depending on whether the writer is using the long scale or the short scale.’
‘…however, British media, including the BBC, which long used “thousand million” for this reason, now use “billion” to mean 109 and “trillion” to mean 1012.’
‘The word trillion describes one of two numerical values, depending on where and how it is used. It is the largest numerical value in everyday non-scientific use in the English language. It comes between a billion and a quadrillion.’