-wards is a suffix that forms adverbs showing direction. For example, if you move or look backwards, you move or look in the direction your back is facing. If you move or look northwards, you move or look towards the north.
Here are some common adverbs ending in -wards:
However, you can be creative and add -wards to other nouns in order to show direction. For example, if you look skywards, you look in the direction of the sky. If you move seawards, you move in the direction of the sea.
In American English, and sometimes in British English, -ward is used instead of '-wards' to form adverbs of direction. For example, instead of saying 'He looked upwards', American speakers usually say 'He looked upward'.
In both British and American English, -ward is used to form adjectives showing direction. For example, you say 'a backward glance' and 'a homeward journey'. These adjectives are usually used in front of nouns.
Both afterwards and afterward are always adverbs, not adjectives. Afterward is more common in American English.
Both towards and toward are always prepositions, not adjectives or adverbs.