# Whats the difference between \[ \] and ( )? **URL:** \ **Category:** Factual Questions\ **Created:** [November 23, 2024, 9:20am UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659 "2024-11-23T09:20:44Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Loggins](https://avatars.discourse-cdn.com/v4/letter/l/74df32/32.png) [@Loggins](https://boards.straightdope.com/u/Loggins)\ **Post date:** [November 24, 2024, 6:55am UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/41 "2024-11-24T06:55:12Z")
Ive wondered about curly bracket. Now im a bit more informed. TY ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [November 24, 2024, 8:33am UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/42 "2024-11-24T08:33:02Z")
Good point. I think I don’t really pay much attention to the exact form of certain marks and characters. The same is probably true of quotes. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [November 24, 2024, 8:35am UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/43 "2024-11-24T08:35:51Z")
Also… Are these: \<\> called 'angle brackets everywhere or just here? (also also those are just the greater than and less than math comparison operators. Are there different forms for actual angle brackets?) ---
**Author:** ![Horatio\_Hellpop](https://avatars.discourse-cdn.com/v4/letter/h/e5b9ba/32.png) [@Horatio\_Hellpop](https://boards.straightdope.com/u/Horatio_Hellpop)\ **Post date:** [November 24, 2024, 9:56am UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/44 "2024-11-24T09:56:16Z")
> Mangetout: > > Also… Are these: \<\> called 'angle brackets everywhere or just here? > > (also also those are just the greater than and less than math comparison operators. Are there different forms for actual angle brackets?) They’re used to format links for web pages. I’ve never seen them called anything but greater than and less than, though. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [November 24, 2024, 12:17pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/45 "2024-11-24T12:17:00Z")
I’ve seen them used informally in sort of emoji-like contexts, but often indicating a slightly more complex or non-standard action than a single emoji would. \ Or sometimes to add HTML-like tagging to a sentence, but in a human-readable sense, \obviously\ ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [November 24, 2024, 2:11pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/46 "2024-11-24T14:11:10Z")
Angle brackets are sometimes used in math for vectors, like this: \langle 3, 4 \rangle Typeset properly, they’re not the same as less than/greater than symbols. 3 \< 4 ---
**Author:** ![Topologist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/topologist/32/3208_2.png) [@Topologist](https://boards.straightdope.com/u/Topologist)\ **Post date:** [November 24, 2024, 5:50pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/47 "2024-11-24T17:50:04Z")
There are several other uses in math as well. For example, \mathbb{R}[x]/\langle x^2+1\rangle is the quotient of the ring of polynomials by _the ideal generated by_ x^2+1, which is what the term in angle brackets represents. And yes, they’re called angle brackets in this context and are distinct from “less than” and “greater than.” In LaTeX, they’re called `\langle` and `\rangle`. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [November 24, 2024, 6:09pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/48 "2024-11-24T18:09:22Z")
langlerangle would be a great user name. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 24, 2024, 7:18pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/49 "2024-11-24T19:18:36Z")
There are also guillemets ‹›«», which French uses to mark quotations. They come in single and double versions, but the single versions also resemble angle brackets (though they’re usually only on the bottom half of the line, like lower-case letters). ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [November 24, 2024, 7:36pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/50 "2024-11-24T19:36:23Z")
> [@Mangetout](#): > > Apropos of not very much, they’re all called ‘brackets’ in UK speech :- (brackets) [square brackets] {curly brackets} Mainly called parentheses here in the US. Certainly called ‘brackets’ if you’re in a font oriented industry but parentheses is such common usage among lay people that even technical documents will have the highly meta clarification ‘(parentheses)’ included. Personally I prefer to call ‘{}’ by the nonstandard name ‘squiggly brackets’. Doesn’t seem to have caught on much though. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [November 24, 2024, 8:30pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/51 "2024-11-24T20:30:44Z")
> [@TriPolar](#): > > but parentheses is such common usage among lay people Yeah, I think it must be very common - I get quite a lot of ‘ummm actually…’ miscorrections whenever I read out () as ‘brackets’. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [November 24, 2024, 10:27pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/52 "2024-11-24T22:27:46Z")
> [@Topologist](#): > > There are several other uses in math as well. For example, \mathbb{R}[x]/\langle x^2+1\rangle is the quotient of the ring of polynomials by _the ideal generated by_ x^2+1, which is what the term in angle brackets represents. And yes, they’re called angle brackets in this context and are distinct from “less than” and “greater than.” In LaTeX, they’re called `\langle` and `\rangle`. Fair enough, and makes sense, but I am sure I have seen regular brackets used more often in the specific context of ideals of rings to denote the ideal generated by a set of elements. Example: \mathbb{R} are the real numbers, \mathbb R\langle x,y\rangle is the free ring over \mathbb{R} generated by [non-commuting] variables x and y, and finally \mathbb{R}\langle x,y\rangle \big/ (x^2+1,\,y^2+1,\,xy+yx) is the algebra of quaternions. ---
**Author:** ![Topologist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/topologist/32/3208_2.png) [@Topologist](https://boards.straightdope.com/u/Topologist)\ **Post date:** [November 25, 2024, 1:01am UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/53 "2024-11-25T01:01:16Z")
It’s definitely one of those things where the notation isn’t set in stone, and authors tend to use whatever they’ve seen before or makes sense to them at the time. I don’t think I’ve seen that notation \mathbb{R}\langle x,y \rangle before, but I work a lot more with commutative rings than noncommutative ones. If you’re going to use that notation, you’ll definitely want a notation for the ideal that doesn’t use angle brackets. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [November 25, 2024, 3:43am UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/54 "2024-11-25T03:43:22Z")
> [@Mangetout](#): > > Apropos of not very much, they’re all called ‘brackets’ in UK speech :- (brackets) [square brackets] {curly brackets} > > I’m sure there are formal contexts in which people call them parentheses, brackets and braces here, but in general speech () are brackets. I mention this because it trips a few people up. Yes. I, in Canada, learned them as round brackets, square brackets, curly brackets, and also angle brackets \<\> (true angle brackets are taller and skinnier than the less-than and greater-than signs I added here), and corner brackets 「 」(used in Japanese text). ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [November 25, 2024, 11:56am UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/55 "2024-11-25T11:56:40Z")
So do you ever use the words “parentheses” or “parenthetical”? ---
**Author:** ![I\_Love\_Me\_Vol.I](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/i_love_me_vol.i/32/521_2.png) [@I\_Love\_Me\_Vol.I](https://boards.straightdope.com/u/I_Love_Me_Vol.I)\ **Post date:** [November 25, 2024, 12:28pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/56 "2024-11-25T12:28:59Z")
> [@Mangetout](#): > > Not sure if it’s worth mentioning, but other ways exist - paired dashes, for example - to set apart a a parenthetical clause in a sentence. I use that writing device sometimes. I prefer to use an an [em dash](https://www.merriam-webster.com/grammar/em-dash-en-dash-how-to-use). Typing a hyphen twice will give you an em dash in some word processing programs but if not, double hyphens work well, IMO. > [@TriPolar](#): > > Certainly **called ‘brackets’ if you’re in a font oriented industry** but parentheses is such common usage among lay people that even technical documents will have the highly meta clarification ‘(parentheses)’ included. [Bolding mine] If font oriented people call parentheses ‘brackets’ then what do they call ‘brackets’? I worked in a print shop for several years (years ago). Parentheses were always called ‘parentheses’. In that shop, at least. Parentheses and brackets are two separate things. ---
**Author:** ![I\_Love\_Me\_Vol.I](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/i_love_me_vol.i/32/521_2.png) [@I\_Love\_Me\_Vol.I](https://boards.straightdope.com/u/I_Love_Me_Vol.I)\ **Post date:** [November 25, 2024, 12:37pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/57 "2024-11-25T12:37:46Z")
[added this to my previous post just above] ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [November 25, 2024, 1:38pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/58 "2024-11-25T13:38:39Z")
> [@I\_Love\_Me\_Vol.I](#): > > Parentheses and brackets are two separate things. Where you live, perhaps. Where I live, brackets are the whole family of paired enclosing marks, with the curved type (being the most common) not requiring any other qualifier than just ‘brackets’. Other types of brackets have a descriptive qualifier such as _square_ or _curly_. ---
**Author:** ![I\_Love\_Me\_Vol.I](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/i_love_me_vol.i/32/521_2.png) [@I\_Love\_Me\_Vol.I](https://boards.straightdope.com/u/I_Love_Me_Vol.I)\ **Post date:** [November 25, 2024, 2:17pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/59 "2024-11-25T14:17:32Z")
> [@Mangetout](#): > > Where you live, perhaps. Where I live, brackets are the whole family of paired enclosing marks, with the curved type (being the most common) not requiring any other qualifier than just ‘brackets’. Yes, quite right. It will depend on where you live and what form of English you’re using. I suppose I was responding to @TriPolar who said that “font-oriented industries” refer to parentheses as ‘brackets’. Perhaps they also weren’t talking about American English but they did say “… parentheses is such common usage among lay people…” which to me implies American English. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [November 25, 2024, 3:30pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659/60 "2024-11-25T15:30:09Z")
Yeah, I would have expected professions such as typography, typesetting and design to use the more formal terms such as parentheses, braces, etc. [Previous page](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659.md?page=2) [Next page](https://boards.straightdope.com/t/whats-the-difference-between-and/1010659.md?page=4)