I read electronics/computing articles, and I find an incredible amount of terms are written either in kanji (almost similar to Chinese) or katakana. There are times when it's confusing as to know why.

For example:




On the other hand there are:




What interests me is the mix of katakana and kanji in these last terms. Is there any reason for this? Why not just stick with one method? I'm sure there is a way to describe アドレス in kanji for the last term. Does mixing them make it easier to understand? It seems like the more recent / well-understood terms by the general public get katakana. The others have kanji bases.

EDIT: There is 不揮発性半導体記憶装置 but would 「不揮発性半導体記憶」 not carry the same meaning as 不揮発性半導体メモリ? It just seems to be a random decision whether a word gets katakana or kanji.

  • Notice that comprehension of English may not be assumed. I've often seen people use "kataka words," just to explain immediately aftewards what they meant in "kanji Japanesese" (eg, CS teachers at the university, introducing words like "reference, continuation, control flow," etc.)
    – Axioplase
    Commented Jul 9, 2012 at 10:40

4 Answers 4


You forgot the other option: abbreviations like IPアドレス, HDD, etc. This is quite common when you start getting long, unwieldy strings of katakana.

I think there are multiple factors going on:

  1. People who work in electronics/computing are more likely to have a good command of English, and know the terms in English, and direct borrowing of English terms is quite natural in that case. Particularly if the meaning of the term in English, in the computing context, is not directly the same as the dictionary meaning of the word, making it more sensible to transliterate rather than translate.

  2. Where there is a pre-existing kanji compound that fits the bill and isn't ambiguous, that will be used.

  3. There is a general trend to use more katakana, so terms that are older, like 半導体, are more likely to have kanji forms.

  4. The person who names the item, or at least gives it the name that sticks, as sometimes there are multiple versions, will have their own personal preferences. (This might be the inventor, the documentation writer, translator, textbook writer...)

Why not just stick with one method?

To turn it about: what would be the benefit of doing so?

In many cases these will be compounds of existing terms, and you're sticking together a concept usually expressed in katakana and one for which a standard kanji term exists, it is logical that the result will be part katakana, part kanji.

To borrow from sawa's example, if "メモリ" has an existing meaning (separate from 記憶), and 不揮発性 as well 半導体 are existing terms, then 不揮発性 + 半導体 + メモリ is an easily understandable compound. There's no particular advantage to replacing the word "メモリ" with a less-used kanji equivalent.

If all the parts exist in katakana, you'll get an all katakana string (although this might end up being shortened: メディタブ I've seen; スマホ is probably as common, if not more, than the full equivalent). If all the parts have kanji then you'd get a long kanji compound (for example: 超々大規模集積回路).

Now for an opinion from somebody in the field, from this blog.

The main reason he gives near the bottom as to why there are a lot of katakana words in IT in particular:

時間がない (there's no time) The pace of the IT industry is fast, and there are constantly new terms/concepts being invented. There isn't the time to come to a consensus on the standard translation for each one. So transliterating into katakana is the easiest way. Even if you were to coin a kanji term, chances are that the majority would just use the katakana word.

  • 3
    IP, HDD are not usually called ローマ字.
    – user458
    Commented Jul 7, 2012 at 16:19
  • 2
    To clarify sawa’s point, in modern Japanese, ローマ字 usually means transliteration of Japanese in the English alphabet. Just “the English alphabet” is 英字 or often アルファベット (where its meaning is taken as the English alphabet by default). Commented Jul 7, 2012 at 23:43
  • For your first point, I agree it does make sense to transliterate than translate. However, what about when that transliterated word gets used in other ways that deviate from the original definition?
    – Chris
    Commented Jul 8, 2012 at 2:24
  • 2
    @Chris: if enough people start using a word in a different way than its original meaning, then it acquires a secondary meaning, is that what you're referring to? I don't think that's different for katakana words compared to kanji words (or indeed English words: computer referred to a person doing a certain job long before it referred to a machine). If you look up 揮発 in a dictionary you'll see meanings relating to "volatile" as in chemistry, not the computing meaning.
    – nkjt
    Commented Jul 8, 2012 at 12:45

Regarding your question after the edit, I think you are poisoned with English. It is the English word "memory" that can mean two different things: stored information and a device that stores information. Do not assume that an English idiosyncracy can be carried into Japanese. The Japanese word 記憶 means stored information but not a device. The Japanese word メモリ means a device but not information.

  • @Sawa: Thanks, that makes sense; however, as you have previously said, it applies only to the last part. It doesn't seem to apply to フラッシュストレージ ..otherwise it would be フラッシュ記憶 if I'm not mistaken.
    – Chris
    Commented Jul 7, 2012 at 3:44
  • 1
    @Chris You are repeating the same mistake. 記憶 does not mean storage (device).
    – user458
    Commented Jul 7, 2012 at 4:18
  • @Sawa: I see. You are correct. I mistakenly thought that フラッシュストレージ referred to a method of storing data, when in fact it is actually a device.
    – Chris
    Commented Jul 7, 2012 at 6:55
  • 3
    You are right, 記憶 does not mean “storage device.” Note that when speaking informally, we refer to 外部記憶装置 also as 外部記憶, but this is probably an abbreviation rather than 記憶 meaning “storage device.” Commented Jul 7, 2012 at 12:31
  • 2
    @TsuyoshiIto In the academic fields of computer science and information technology, メモリ (rather than メモリー) is almost equivalent to 記憶. This is not an abbreviation, but a kind of translation rule ("memory" = "記憶"). You can find 記憶 used to describe a device and メモリ used to describe information in technical books. For example, 仮想記憶 and 仮想メモリ are the same thing. Microsoft uses even 仮想メモリー. In addition, I must say that we have another word メモリー (rather than メモリ) in nontechnical everyday contexts, such as 愛のメモリー (song by 松崎しげる). Since computers got popular, this meaning had been common.
    – Gradius
    Commented Jul 15, 2012 at 19:47

If the word, with a given meaning, got established outside of Japan and was then introduced, then what I find is that if the person introducing the term has good enough English that they are thinking in English, they'll tend to write the word in katakana. The same if a non-specialist translator is being used: their choices are:

  • Write the word as it sounds
  • Contact experts in the field to get an explanation of the concept in Japanese, and agree a kanji compound that captures the meaning reasonably well.

Whether they are getting paid by the source word, of by the hour, the katakana option is more likely to be chosen. For a simultaneous translator, they simply don't have time: they katakana-ize any unknown word.

Homegrown concepts, especially incremental advances on concepts that already use kanji, are more likely to be in kanji.

What actually happens with a lot of words is they get introduced to Japan by multiple people. In many cases they are independently invented, in different countries. So you start off with multiple words for the same thing: some people have gone for katakana, some for kanji. If the concept is quite specialized and is mainly used in the scientific community (in which I include the research divisions of large companies) then the kanji term has more chance of sticking. If it is more a consumer-facing concept, then marketing divisions are more likely to use the katakana term.


words from foreign languages (other than Chinese language) that are used in Japanese are always in katakana. Kanji is useful to distinguish between two words with same phonetics but diffrent meanings

  • Pre-Meiji imports from languages other than Chinese usually had Kanji assigned as well, such as 麺麭【パン】and 煙草【タバコ】. Their use has declined since then (understandable, when you look at the complexity of パン), but they do exist.
    – Kaji
    Commented Mar 29, 2014 at 4:13

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