Glossary
X
18 terms.
- X.400
A CCITT and ISO series of recommendations (ISO/IEC 10021) for message handling. It defines an Interpersonal Messaging System that runs over a store-and-forward Message Transfer System.
Like I'm five A different kind of email system, with its own rules, that was designed by international standards bodies.
- X.400
An international standard for message handling systems defined by the CCITT (now ITU), used by many organizations outside the Internet for electronic mail.
Like I'm five An official but different way to send email, used mainly in businesses and governments outside the Internet.
- X.500
A standardized distributed directory system defined by ISO that uses a hierarchical tree structure to store information about network resources and users.
Like I'm five A big shared phone book where information is organized in a tree, like a family tree.
- X.500
An OSI standard protocol for a distributed, hierarchical directory service defined by CCITT (now ITU) for storing and retrieving information about people and resources.
Like I'm five An international system for a giant phone book that works across many organizations and computers.
- X.500 Directory
The OSI Directory, a very general naming framework whose entries are organised in a tree and named by attributes such as country, organisation and common name.
Like I'm five A giant, well organised phone book where every entry has a long, full name.
- X.509
The standard format for public-key certificates. RFC 5280 profiles version 3 certificates and version 2 CRLs for the Internet.
Like I'm five The standard layout of a digital ID card.
Used in RFC 1422 RFC 1588 RFC 1848 RFC 2116 RFC 2312 RFC 2559 RFC 3039 RFC 3163 RFC 3280 RFC 3335 RFC 3647 RFC 3709 RFC 3739 RFC 4043 RFC 4334 RFC 4398 RFC 4476 RFC 4514 RFC 4519 RFC 4523 RFC 4630 RFC 5024 RFC 5081 RFC 5126 and 30 more
- X.509 certificate
A signed record that binds a public key to an identity, issued by a certificate authority. CMS uses certificates to find the key needed to check a signature or to encrypt to a recipient.
Like I'm five An ID card for a key, stamped by someone everybody trusts.
Used in RFC 1421 RFC 1507 RFC 2025 RFC 2218 RFC 2312 RFC 2315 RFC 2316 RFC 2437 RFC 2459 RFC 2510 RFC 2511 RFC 2528 RFC 2560 RFC 2585 RFC 2587 RFC 2660 RFC 2798 RFC 2801 RFC 2818 RFC 2829 RFC 2943 RFC 2951 RFC 2986 RFC 3039 and 265 more
- X11 forwarding
Letting graphical programs on a remote machine show their windows on your local screen by tunneling the X11 protocol through SSH channels.
Like I'm five Sending a picture of a remote program's window through the tunnel to your own screen.
- XCAP
The XML Configuration Access Protocol lets clients read and change parts of XML documents stored on a server, using HTTP. Each kind of document is handled by an application usage.
Like I'm five A way to open a shared document on a server and change just one line of it.
- XDR (External Data Representation)
A standard notation and encoding for describing data structures so that different computers can exchange them in an identical way. NFS messages are described in it.
Like I'm five A common drawing style that everyone agrees on, so two computers read the same message the same way.
Used in RFC 1094 RFC 5531 RFC 5662 RFC 5666 RFC 7531 RFC 7863 RFC 8166 RFC 8178
- XML
The Extensible Markup Language, a text format that nests named elements and attributes to describe structured data.
Like I'm five A way of writing information in labelled boxes inside bigger labelled boxes.
- XML namespace
A URI that marks which specification an XML element belongs to, so that elements from different specifications do not clash.
Like I'm five A label on each word telling which rulebook it comes from.
Used in RFC 3076 RFC 3470 RFC 3863 RFC 4287 RFC 4765 RFC 4854 RFC 5261 RFC 6321 RFC 6351 RFC 6848 RFC 7203 RFC 7950 RFC 8544 RFC 9038
- XML schema
A formal description of which elements, attributes and values an XML document may contain, used to check whether a document is valid.
Like I'm five A rulebook that says exactly which boxes a form has and what can go in each.
- XML stream
A container for XML sent in one direction over a connection. XMPP uses two, one in each direction, and each starts with a stream header and ends with a closing tag.
Like I'm five A long, one-way note that keeps getting longer as new pieces are added.
Used in RFC 2376 RFC 2629 RFC 2803 RFC 3106 RFC 3120 RFC 3354 RFC 3920 RFC 4331 RFC 4741 RFC 4767 RFC 4839 RFC 4911 RFC 4913 RFC 4914 RFC 4918 RFC 4991 RFC 5263 RFC 5277 RFC 5388 RFC 5730 RFC 6022 RFC 6110 RFC 6120 RFC 6121 and 9 more
- XMPP
The Extensible Messaging and Presence Protocol: an XML-based protocol for real-time messaging, presence and request-response between clients and servers, and between servers. Defined in RFC 6120.
Like I'm five A set of rules chat programs use to talk to each other.
Used in RFC 3920 RFC 3921 RFC 3922 RFC 3923 RFC 4479 RFC 4622 RFC 4770 RFC 4979 RFC 5122 RFC 5435 RFC 5437 RFC 6120 RFC 6121 RFC 6122 RFC 6132 RFC 6366 RFC 6473 RFC 6885 RFC 7081 RFC 7165 RFC 7247 RFC 7248 RFC 7259 RFC 7395 and 13 more
- XOR (Exclusive Or)
A bitwise operation that combines two binary values; it outputs 1 when the inputs differ and 0 when they match. XOR has the property that A XOR B XOR B equals A, making it useful for error correction.
Like I'm five A magic operation where doing it twice undoes itself: A XOR B XOR B gets you back to A.
- XPath
A query language that picks out nodes from an XML document by describing a path through its tree structure.
Like I'm five An address that points to one spot, or several spots, inside a big tree of information.
- XPath Expression
A string that selects nodes within an XML document using a path-like syntax, for example doc/elem[@a='foo'] selects elem elements with an attribute a equal to 'foo'.
Like I'm five A way to point to specific parts of an XML document using a path-like notation.