Upward means moving or facing towards a higher place. An upward slope, upward trend, upward mobility.
The figurative uses are commoner than the literal: an upward trend, upward pressure on prices, upward mobility meaning movement to a higher social class. As an adverb, British English prefers upwards and American English upward, and both are correct. Note upwards of, which means more than — upwards of four hundred people — and is a genuinely different construction.
1adjectiveupwardMoving or facing towards a higher place.
“The upward path to the castle was steep and rocky.”
2adverbdirectionIn that direction.
“The balloon floated upward until it disappeared into the clouds.”
upward is a direction.
Old English upweardes is up plus -weard, the suffix meaning turned towards. Toward, forward and backward are all built the same way, and the -s on upwards is an old genitive.
Old English
upweardes
English, today
upward
From Old English upweardes, equivalent to up + ward.
Etymology from Wiktionary, CC BY-SA