Comparing "yihou" "ranhou" "houlai"

While both 以后 (yǐhòu) and 后来 (hòulái) can mean "after," they have distinct uses.

Used for the future in general

以后 is used when talking about things that happen at some unspecified point in the future.

以后，⋯⋯

以后，我打算去中国找工作。 Yǐhòu, wǒ dǎsuàn qù Zhōngguó zhǎo gōngzuò.Later, I plan to go to China to look for work.
他以后不想住在大城市。 Tā yǐhòu bù xiǎng zhù zài dà chéngshì.He doesn't want to live in big cities later.
我以后想自己开公司。 Wǒ yǐhòu xiǎng zìjǐ kāi gōngsī.I want to start up my own business later.

以后 can be used to describe actions or events that occur after a specific time (and the time must be given).

Time + 以后，⋯⋯

Note that the time can be specific (like a date or time) or broad (like an event, action, or occurrence).

两个星期以后，我要回美国。 Liǎng gè xīngqī yǐhòu, wǒ yào huí Měiguó.After two weeks, I'm going to return to the USA.
老板一个小时以后回来。 Lǎobǎn yī gè xiǎoshí yǐhòu huílái. The boss will come back in an hour.
从那以后，我再也没见过她。 Cóng nà yǐhòu, wǒ zài yě méi jiàn guo tā.After that time, I never saw her again.

后来 is used to sequence two events that have already occurred. It is the Chinese equivalent of the English word "afterward."

Also note that 后来 is a time noun, and it can only be used on its own.

Past Event 1 ，后来 + Past Event 2

去年我们分手了，后来再也没见过她。 Qùnián wǒmen fēnshǒu le, hòulái zài yě méi jiàn guo tā.We broke up last year, after that, I never saw her again.
他在我们公司工作过两年，后来换工作了。 Tā zài wǒmen gōngsī gōngzuò guo liǎng nián, hòulái huàn gōngzuò le.He worked for our company for two years. Then he changed his job.