What is a MIME type

Question

I have been reading about how to build plug-ins and this  MIME type  keeps getting discussed in it  I have tried to look into it and know that it is Multipurpose Internet Mail Extensions  MIME  but no suitable explanation of how it relates to browser plug-ins  as in what I need to know about it for building plug-ins  is provided  please explain in clear and simple words  What is it  Why do plug-ins have a MIME type

User · Answer

Explanation by analogy

Imagine that you wrote a letter to your pen pal but that you wrote it in different languages each time.

For example, you might have chosen to write your first letter in Tamil, and the second in German etc.

In order for your friend to translate those letters, your friend would need to:

(i) identify the language type, and
(ii) and then translate it accordingly. But identifying a language is not that easy - it's going to take a lot of computational energy. It would be much easier if you wrote the language you are sending across on the top of your letter - that would make life a lot easier for your friend.

So then, in order to highlight the language you are writing in, you simple annotate the language (e.g. "French") on the top of your letter.

How would your friend know or be able to read or distinguish between the different language types you are specifying at the top of your letter? That's easy: you agree upon this beforehand.

Tying the analogy back in with HTML

Because there are different types of data formats which need to be sent over the internet, specifying the data type up front would allow the corresponding client to properly interpret and render the data accordingly to the user.

Why do we have different data formats?

Principally because they serve different purposes and have different abilities.

For example, a PDF format is very different from a picture format - which is also different from a sound format - both serve very different purposes and accordingly are written different prior to being sent over the internet.

User · Answer

MIME stands for Multipurpose Internet Mail Extensions  It s a way of identifying files on the Internet according to their nature and format    For example  using the Content-type header value defined in a HTTP response  the browser can open the file with the proper extension plugin      Internet Media Type  also Content-type  is the same as a MIME type  MIME types were originally created for emails sent using the SMTP protocol  Nowadays  this standard is used in a lot of other protocols  hence the new naming convention  Internet Media Type        A MIME type is a string identifier composed of two parts  a type and a subtype     The  type  refers to a logical grouping of many MIME types that are closely related to each other  it s no more than a high level category    subtypes  are specific to one file type within the  type       The x- prefix of a MIME subtype simply means that it s non-standard  The vnd prefix means that the MIME value is vendor specific   Source

User · Answer

I couldn t possibly explain it better than wikipedia does  http   en wikipedia org wiki MIME type     In addition to e-mail applications  Web browsers also support various MIME types  This enables the browser to display or output files that are not in HTML format    IOW  it helps the browser  or content consumer  because it may not just be a browser  determine what content they are about to consume  this means a browser may be able to make a decision on the correct plugin to use to display content  or a media player may be able to load up the correct codec or plugin

User · Answer

MIME stands for Multi-purpose Internet Mail Extensions  MIME types form a standard way of classifying file types on the Internet  Internet programs such as Web servers and browsers all have a list of MIME types  so that they can transfer files of the same type in the same way  no matter what operating system they are working in   A MIME type has two parts  a type and a subtype  They are separated by a slash      For example  the MIME type for Microsoft Word files is application and the subtype is msword  Together  the complete MIME type is application msword   Although there is a complete list of MIME types  it does not list the extensions associated with the files  nor a description of the file type  This means that if you want to find the MIME type for a certain kind of file  it can be difficult  Sometimes you have to look through the list and make a guess as to the MIME type of the file you are concerned with

User · Answer

It is useful to think of MIME in the context of the client-server model  Clients and servers communicate over what is known as the HTTP protocol  In a http request or response  we can have a body  The Content-type or MIME type specifies what is the type of the body  like text javascript or something else like audio  video  etc  However  MIME types are not limited just to HTTP  As the name suggests  MIME stands for Multipurpose Internet Mail Extensions  Originally  SMTP only supported ascii-encodings  However  there as a need for more  We could use MIME to slap a label on the content being transmitted or received

User · Answer

A MIME type is a label used to identify a type of data  It is used so software can know how to handle the data  It serves the same purpose on the Internet that file extensions do on Microsoft Windows   So if a server says  This is text html  the client can go  Ah  this is an HTML document  I can render that internally   while if the server says  This is application pdf  the client can go  Ah  I need to launch the FoxIt PDF Reader plugin that the user has installed and that has registered itself as the application pdf handler    You ll most commonly find them in the headers of HTTP messages  to describe the content that an HTTP server is responding with or the formatting of the data that is being POSTed in a request  and in email headers  to describe the message format and attachments

[browser] What is a MIME type?

Explanation by analogy

Tying the analogy back in with HTML

Examples related to browser

Examples related to firefox-addon

Examples related to mime-types