HTTP status message definitions
The ability to request a resource via a unique URL. Once a client is authenticated, the state of the client should not affect access to an addressable resource.
Application programming interface. A set of pre-determined functions that are exposed by an application or service for use by third-party developers. Web services will usually expose a documented API to detail how developers should interface with the service.
Software used for viewing web content. See also user agent.
- Canonical URL
The one authoritatively correct URL for a resource. When a resource can be accessed via multiple URLs, a canonical URL should be chosen. All alias URLs for a resource should redirect to the canonical URL to enforce its authority.
- Deep linking
The act of linking to a web resource which is not the homepage of the website being linked to.
- Denial of Service (DoS) attack
An electronic attack whose purpose is to prohibit the target server use of a program or an entire system. For example: in a HTTP context it is common for an attacker to bombard a server with many requests until the server is unable to respond appropriately to legitimate HTTP requests.
- GET method
- Header field
HyperText Transfer Protocol. A cross-platform open standard communication protocol used to send and receive information on the internet between web browsers and web servers.
- POST method
A HTTP request method. POST is not an acronym or an initialism, but is capitalised out of convention. The POST method should be used when sending information to a server or interacting with a web application to change its state.
HTTP request. Every time a user agent requires access to a web resource it performs a request. For example: each web page loaded in a browser will often require several requests are made (one for the page itself and one for each image, script file, or other resource embedded in the page).
HTTP resource. A file or a defined output of an application/database that can be served via HTTP to a user agent. Each unique resource should have at least one unique URL, this ensures the addressability of the resource.
HTTP response. Under normal operating conditions, for each request made by a user agent, a HTTP response will be returned by the server. The nature of the response depends on the request made and the current state of the server, but a common response is to send a status, along with headers and an entity-body containing the requested resource.
HTTP server. Software running on a host computer that listens for incoming requests and responds according to the HTTP protocol. A related term is web server. A web server will almost always act as a HTTP server, but may also support other protocols/functions.
HTTP status. A status code sent with a response to summarise the status of the requested resource. For example: a well known HTTP status is 404, this status is sent by a server when the requested resource cannot be located (or in a few other edge cases). Another common HTTP status is 200, this status is sent by the server when a document is found successfully, and is usually returned bundled with the requested document.
Universal resource locator. A string of characters used to locate a resource available via the Internet.
- URL normalisation
- User agent
Software used to access web content. This may be browser software (for end users) or more automated software agent that works on behalf of a person or organisation (example: a search engine indexing robot).
- Web application
Software system hosted on a server targeted at human users.
- Web service
Software system designed to support interoperable machine to machine interaction over a network. Web services are frequently just Web APIs that can be accessed over a network, such as the internet, and executed on a remote system hosting the service.