What's the difference between 関する【かんする】, 関係する【かんけいする】, and 関連する【かんれんする】?


What's the difference between 関する【かんする】, 関係する【かんけいする】, and 関連する【かんれんする】?

I've tried looking for an answer on HiNative, and while I did find two
answers, I didn't quite understand the differences. I then also tried reading
the definitions for these words on dictionary.goo.ne.jp, which also didn't
help, and tatoeba.org only has one sentence containing 関連する【かんれんする】. Looking
the words up on jisho.org and eow.alc.co.jp didn't help either.




**関する** literally means "to regard" or "to concern", but it's almost always
used as a modifier (either adjectivally or adverbially) rather than as an
ordinary predicate. It's used to tell what you are talking about.

  * 彼女に関する話  
a story regarding her

  * この件に関して話す  
to discuss concerning this issue

  * 明日の会議に関しては、…  
As for the meeting tomorrow, ...

**関係する** and **関連する** both mean "to be related" in English, and they are often
indeed interchangeable. 関連 tends to refer to more indirect relationships like
"different but conceptually similar", "have something in common" or "people
are often reminded of this". On the other hand, 関係 tends to refer to more
direct relationships like knowing or affecting each other.

For example, Babe Ruth and [Sadaharu
Oh](https://en.wikipedia.org/wiki/Sadaharu_Oh) have a 関連 (they are both known
as great home run batters) but people usually do not say they have a 関係 (they
didn't know each other personally). We say "CPUとメモリの関係" but not "CPUとメモリの関連"
because they are closely tied and work together. In Wikipedia, "See Also"
sections are called 関連記事 in the Japanese version because each article is
basically independent and does not affect others.




**関する** literally means "to regard" or "to concern", but it's almost always
used as a modifier (either adjectivally or adverbially) rather than as an
ordinary predicate. It's used to tell what you are talking about.

  * 彼女に関する話  
a story regarding her

  * この件に関して話す  
to discuss concerning this issue

  * 明日の会議に関しては、…  
As for the meeting tomorrow, ...

**関係する** and **関連する** both mean "to be related" in English, and they are often
indeed interchangeable. 関連 tends to refer to more indirect relationships like
"different but conceptually similar", "have something in common" or "people
are often reminded of this". On the other hand, 関係 tends to refer to more
direct relationships like knowing or affecting each other.

For example, Babe Ruth and [Sadaharu
Oh](https://en.wikipedia.org/wiki/Sadaharu_Oh) have a 関連 (they are both known
as great home run batters) but people usually do not say they have a 関係 (they
didn't know each other personally). We say "CPUとメモリの関係" but not "CPUとメモリの関連"
because they are closely tied and work together. In Wikipedia, "See Also"
sections are called 関連記事 in the Japanese version because each article is
basically independent and does not affect others.

