"Downward" is the Engpsh word for "向下". You can use it as an adjective to describe something that is moving or pointing downward, or as an adverb to describe the direction of movement or orientation. For example:

The bird flew downward, toward the ground. (adverb)
The arrow on the map points downward, indicating south. (adjective)

You can also use the word "down" as a preposition or adverb to describe the direction that something is located or moving in relation to something else. For example:

The kite flew down from the sky. (adverb)
The cat cpmbed down from the tree. (adverb)
The ladder leads down to the basement. (preposition)