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Content-Type
A media type (also known as a MIME type) is a two-part identifier for file formats and format contents transmitted on the Internet. The Internet Assigned Numbers Authority (IANA) is the official authority for the standardization and publication of these classifications. Media types were originally defined in Request for Comments (MIME) Part One: Format of Internet Message Bodies (Nov 1996) in November 1996 as a part of the ''MIME (Multipurpose Internet Mail Extensions)'' specification, for denoting type of email message content and attachments; hence the original name, ''MIME type''. Media types are also used by other internet protocols such as HTTP and document file formats such as HTML, for similar purposes. Naming A media type consists of a ''type'' and a ''subtype'', which is further structured into a ''tree''. A media type can optionally define a ''suffix'' and ''parameters'': : As of November 1996, the registered types were: , , , , , and . By December 2020, the register ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIME
Multipurpose Internet Mail Extensions (MIME) is an Internet standard that extends the format of email messages to support text in character sets other than ASCII, as well as attachments of audio, video, images, and application programs. Message bodies may consist of multiple parts, and header information may be specified in non-ASCII character sets. Email messages with MIME formatting are typically transmitted with standard protocols, such as the Simple Mail Transfer Protocol (SMTP), the Post Office Protocol (POP), and the Internet Message Access Protocol (IMAP). The MIME standard is specified in a series of requests for comments: , , , , and . The integration with SMTP email is specified in and . Although the MIME formalism was designed mainly for SMTP, its content types are also important in other communication protocols. In the HyperText Transfer Protocol (HTTP) for the World Wide Web, servers insert a MIME header field at the beginning of any Web transmission. Clients ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HTTP
The Hypertext Transfer Protocol (HTTP) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web, where hypertext documents include hyperlinks to other resources that the user can easily access, for example by a mouse click or by tapping the screen in a web browser. Development of HTTP was initiated by Tim Berners-Lee at CERN in 1989 and summarized in a simple document describing the behavior of a client and a server using the first HTTP protocol version that was named 0.9. That first version of HTTP protocol soon evolved into a more elaborated version that was the first draft toward a far future version 1.0. Development of early HTTP Requests for Comments (RFCs) started a few years later and it was a coordinated effort by the Internet Engineering Task Force (IETF) and the World Wide Web Consortium (W3C), with work later moving to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Request For Comments
A Request for Comments (RFC) is a publication in a series from the principal technical development and standards-setting bodies for the Internet, most prominently the Internet Engineering Task Force (IETF). An RFC is authored by individuals or groups of engineers and computer scientists in the form of a memorandum describing methods, behaviors, research, or innovations applicable to the working of the Internet and Internet-connected systems. It is submitted either for peer review or to convey new concepts, information, or, occasionally, engineering humor. The IETF adopts some of the proposals published as RFCs as Internet Standards. However, many RFCs are informational or experimental in nature and are not standards. The RFC system was invented by Steve Crocker in 1969 to help record unofficial notes on the development of ARPANET. RFCs have since become official documents of Internet specifications, communications protocols, procedures, and events. According to Crocker, the doc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Email
Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email was thus conceived as the electronic ( digital) version of, or counterpart to, mail, at a time when "mail" meant only physical mail (hence '' e- + mail''). Email later became a ubiquitous (very widely used) communication medium, to the point that in current use, an email address is often treated as a basic and necessary part of many processes in business, commerce, government, education, entertainment, and other spheres of daily life in most countries. ''Email'' is the medium, and each message sent therewith is also called an ''email.'' The term is a mass noun. Email operates across computer networks, primarily the Internet, and also local area networks. Today's email systems are based on a store-and-forward model. Email servers accept, forward, deliver, and store messages. Neither the users nor their computers are required to be online simult ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Content Sniffing
Content sniffing, also known as media type sniffing or MIME sniffing, is the practice of inspecting the content of a byte stream to attempt to deduce the file format of the data within it. Content sniffing is generally used to compensate for a lack of accurate metadata that would otherwise be required to enable the file to be interpreted correctly. Content sniffing techniques tend to use a mixture of techniques that rely on the redundancy found in most file formats: looking for file signatures and magic numbers, and heuristics including searching for well-known representative substrings, the use of byte frequency and ''n''-gram tables, and Bayesian inference. MIME (Multipurpose Internet Mail Extensions) sniffing was, and still is, used by some web browsers, including notably Microsoft's Internet Explorer, in an attempt to help web sites which do not correctly signal the MIME type of web content display. However, doing this opens up a serious security vulnerability, in which, by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IANA
The Internet Assigned Numbers Authority (IANA) is a standards organization that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System (DNS), media types, and other Internet Protocol-related symbols and Internet numbers. Currently it is a function of ICANN, a nonprofit private American corporation established in 1998 primarily for this purpose under a United States Department of Commerce contract. ICANN managed IANA directly from 1998 through 2016, when it was transferred to Public Technical Identifiers (PTI), an affiliate of ICANN that operates IANA today. Before it, IANA was administered principally by Jon Postel at the Information Sciences Institute (ISI) of the University of Southern California (USC) situated at Marina Del Rey (Los Angeles), under a contract USC/ISI had with the United States Department of Defense. In addition, five regional Internet registries delegate number resources to their custom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Content Negotiation
Content negotiation refers to mechanisms defined as a part of HTTP that make it possible to serve different versions of a document (or more generally, representations of a resource) at the same URI, so that user agents can specify which version fits their capabilities the best. One classical use of this mechanism is to serve an image in GIF or PNG format, so that a browser that cannot display PNG images (e.g. MS Internet Explorer 4) will be served the GIF version. A resource may be available in several different representations; for example, it might be available in different languages or different media types. One way of selecting the most appropriate choice is to give the user an index page and let them select the most appropriate choice; however it is often possible to automate the choice based on some selection criteria. Mechanisms HTTP provides for several different content negotiation mechanisms including: server-driven (or proactive), agent-driven (or reactive), transparen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metadata
Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive metadata – the descriptive information about a resource. It is used for discovery and identification. It includes elements such as title, abstract, author, and keywords. * Structural metadata – metadata about containers of data and indicates how compound objects are put together, for example, how pages are ordered to form chapters. It describes the types, versions, relationships, and other characteristics of digital materials. * Administrative metadata – the information to help manage a resource, like resource type, permissions, and when and how it was created. * Reference metadata – the information about the contents and quality of statistical data. * Statistical metadata – also called process data, may describe processes that collect, process, or produce st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer File Formats
A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as programs. These programs enable computers to perform a wide range of tasks. A computer system is a nominally complete computer that includes the hardware, operating system (main software), and peripheral equipment needed and used for full operation. This term may also refer to a group of computers that are linked and function together, such as a computer network or computer cluster. A broad range of industrial and consumer products use computers as control systems. Simple special-purpose devices like microwave ovens and remote controls are included, as are factory devices like industrial robots and computer-aided design, as well as general-purpose devices like personal computers and mobile devices like smartphones. Computers power the Internet, which links bil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Architecture
World Wide Web topology is the network topology of the World Wide Web, as seen as a network of web pages connected by hyperlinks. The Jellyfish and Bow Tie models are two attempts at modeling the topology of hyperlinks between web pages. Models of web page topology Jellyfish Model The simplistic Jellyfish model of the World Wide Web centers around a large strongly connected core of high-degree web pages that form a clique; pages such that there is a path from any page within the core to any other page. In other words, starting from any node within the core, it is possible to visit any other node in the core just by clicking hyperlinks. From there, a distinction is made between pages of single degree and those of higher order degree. Pages with many links form rings around the center, with all such pages that are a single link away from the core making up the first ring, all such pages that are two links away from the core making up the second ring, and so on. Then from each ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filename Extension
A filename extension, file name extension or file extension is a suffix to the name of a computer file (e.g., .txt, .docx, .md). The extension indicates a characteristic of the file contents or its intended use. A filename extension is typically delimited from the rest of the filename with a full stop (period), but in some systems it is separated with spaces. Other extension formats include dashes and/or underscores on early versions of Linux and some versions of IBM AIX. Some file systems implement filename extensions as a feature of the file system itself and may limit the length and format of the extension, while others treat filename extensions as part of the filename without special distinction. Usage Filename extensions may be considered a type of metadata. They are commonly used to imply information about the way data might be stored in the file. The exact definition, giving the criteria for deciding what part of the file name is its extension, belongs to the rules of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XML And MIME
There are two MIME assignments for XML data. These are: *application/xml (RFC 7303, previously RFC 3023) *text/xml (RFC 7303, previously RFC 3023) However, since the introduction of RFC 7303, these are to be regarded as the same in all aspects except name. Because of the wide variety of documents that can be expressed using an XML syntax, additional MIME types are needed to differentiate between languages. XML-based formats add a suffix of ''+xml'' to their own MIME type; this convention is defined in (RFC 7303). ''The following are some examples of common XML media types:'' *Registered ** Extensible HyperText Markup Language (XHTML): application/xhtml+xml (RFC 3236) ** Atom: application/atom+xml (RFC 4287) ** Extensible Stylesheet Language Transformations (XSLT): 'application/xslt+xml'' ** Scalable Vector Graphics ( SVG): 'image/svg+xml'' ** Mathematical Markup Language (MathML): application/mathml+xml *Registration-In-Progress ** application/akn+xml ** application/rif+xml *Un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
