Difference between 発展、発達、and 開発


What is the difference between 発展、発達、and 開発?

According to my textbook, they all mean development. I know that they cannot
be used interchangeably, but I don't know when to use each of them.

I know the kanji 開 means to open, so I'd assume 開発 is used when something new
is developed. Is that correct?

However, I don't know the meanings of the other kanji to distinguish the
difference.




開発 is clearly different from the other two. 開発 means creation, engineering,
etc., and 開発する is transitive. コンピュータを開発する means to create/build/engineer
computers. As you pointed out, 開発(する) can be used when something new is
created.

発展 and 発達 share the similar meaning to a certain extent. コンピュータの発展 and
コンピュータの発達 both refer to the advancement of the computer technology in general.
Both of these are intransitive when followed by する (i.e. コンピュータが発達する, not
*コンピュータを発達する)

The difference of 発展 and 発達 are:

  * 発達 is more like sophistication, reaching maturity, increasing complexity, etc., while 発展 is closer to prosperity. For example, 都市の発達 tend to refer to a maturation of infrastructure, economy, or the system of politics, while 都市の発展 tend to refer to an expansion of the territory, increase of the population, etc.
  * The development of a body/organ/tumor/etc is almost always 発達. 「子どもの成長と発達」「精神の発達」「イルカの脳は発達している」
  * Additionally, 発展 sometimes means "to change", "to evolve." 「事件に発展する (develop into an incident)」「発展問題 (non-straightforward/advanced problem in a textbook)」




開発 is clearly different from the other two. 開発 means creation, engineering,
etc., and 開発する is transitive. コンピュータを開発する means to create/build/engineer
computers. As you pointed out, 開発(する) can be used when something new is
created.

発展 and 発達 share the similar meaning to a certain extent. コンピュータの発展 and
コンピュータの発達 both refer to the advancement of the computer technology in general.
Both of these are intransitive when followed by する (i.e. コンピュータが発達する, not
*コンピュータを発達する)

The difference of 発展 and 発達 are:

  * 発達 is more like sophistication, reaching maturity, increasing complexity, etc., while 発展 is closer to prosperity. For example, 都市の発達 tend to refer to a maturation of infrastructure, economy, or the system of politics, while 都市の発展 tend to refer to an expansion of the territory, increase of the population, etc.
  * The development of a body/organ/tumor/etc is almost always 発達. 「子どもの成長と発達」「精神の発達」「イルカの脳は発達している」
  * Additionally, 発展 sometimes means "to change", "to evolve." 「事件に発展する (develop into an incident)」「発展問題 (non-straightforward/advanced problem in a textbook)」

