‘往后’ is an adverb meaning 'from now on' or 'in the future', emphasizing time moving forward from the present moment. It literally combines 往 (wǎng, 'toward') and 后 (hòu, 'behind' or 'after'), so together it conveys the idea of 'toward what comes after' — i.e., the future. It is commonly used in both spoken and written Chinese to mark a temporal boundary starting now and extending onward.

Unlike ‘以后’ (yǐhòu), which can refer to any point after a specified time (e.g., 'after the meeting'), ‘往后’ almost always anchors to the present unless explicitly modified (e.g., ‘从今天往后’). It carries a slightly formal or reflective tone and often appears in advice, resolutions, or summaries — for instance, when someone resolves to change a habit or looks ahead in planning. It does not mean 'backward' in physical space; that sense belongs to ‘向后’ or ‘往后退’.