向 (xiàng) is a preposition that means "towards", and is used often when expressing or referring to a certain point in Chinese grammar.

Structure
When used as a preposition, "向" indicates an action that is performed towards a reference point, but doesn't have any actual motion towards that point. An example of this in English is, "She looked inside the window." Note that there is no movement in the action.

Examples

Tā yì zhí xiànɡ wǒ zhāo shǒu.
她 一直 向 我 招手。
She kept waving to me.

Note that whereas in English we would say "learn from someone", in Chinese this would be expressed as "learn toward someone", as in the last example sentence. Refer to the following example (and famous propaganda slogan):

xiànɡ léi fēnɡ tónɡ zhì xué xí!
向 雷锋 同志 学习 ！
Learn from Comrade Lei Feng!