不如 (bùrú) can be used to make comparisons in a similar way as the 比 structure. In its simplest form 不如 is used to convey that A is 'not as good as' B. Unlike the 比 structure, when used in this way, the adjective or verb can be omitted.
Simple form
Basic Structure
A + 不如 + B
Examples
我 感觉看 电影 不如 看 电视剧。
浙江 人 特别 会 做 生意,连 广东 人 都不如他们!
Complex form
When an adjective or verb is added to the structure it can then be used to mean A is not as 'adjective' as B, or A does not 'verb' as well as B:
Basic Structure
A (verb) + 不如 + B + adjective/verb
Examples
我 不如 姚明 高。
城市 的 生活 环境 不如 乡下 舒服。
他 用 Excel表格 不如 我 用 得 好。
这个 语法点 不如 前面的 那个 解释 得 清楚。
不如 as an adverb
Basic Structure
不如 + Verb/[verb phrase]
When facing a choice, 不如 can also be used to mean "might as well" to emphasize the choice is the better of two options. When used like this, it is similar in meaning to 不妨.
Examples
既然 已经 做了 一半 了,你 不如 坚持 下去。
与其 空想,不如 马上 行动,做 出 点儿 成绩。
As in the last example sentence, 不如 often occurs in the 与其...不如 structure, meaning "rather than X... might as well Y".