In this section we define a number of terms used in the
Research in a Connected World book. We have aimed to keep these definitions
simple to aid understanding of the core concepts rather than trying to come up
with definitive definitions of what are often very complex and ill-defined
concepts.
- Definition 1: Cloud
An infrastructure that makes use of virtualisation technologies to provide on-
demand services to users. Clouds provide access to dynamically scalable
resources reserved for individual users within a shared infrastructure. Like
grids, clouds can be private (in-house), community-specific or public. Access to
clouds is often provided through
web
services.
- See Also: Grid, Web Service
- Definition 2: Grid
A type of distributed computing infrastructure. Grids can exist within
organisations (private grids, campus grids) but often span organisational
boundaries. The
The EGEE grid infrastructure
is an example of an international grid infrastructure.
- See Also: Cloud
- Definition 3: Ontology
A description of a set of concepts and their relationships within a given domain. Ontologies can be used as a basis for automatic reasoning.
- Definition 4: RDF
Resource Description Framework: a set of specifications for data representation
that facilitate the conceptual representation of data by forming subject-
predicate-object style expressions. RDF is a core component of the
Semantic Web
- See Also: Ontology, Semantic Web
- Definition 5: REST(-ful) Service
A
web service that follows specific
architectural principles. More often than not, REST-ful services are
implementing the standard
HTTP protocol.
- See Also: Web Service, HTTP Protocol
- Definition 6: Semantic Web
The plan to 'semantically annotate' data that is available on the web, thus enabling it to be processed more automatically. An example is that a postal address would not be just written like an address (making it recognisable by a human reader as an address) but also be 'tagged' so that a computer can relate the data to the concept of a postal address.
- See Also: RDF
- Definition 7: Web Service
A service that can be invoked across a network using an machine-to-machine
interface that ensures interoperability across system boundaries.
- See Also: REST(-ful) service, WSDL
- Definition 8: WSDL
Web Services Description Language: a language used to describe
web service interfaces, specifying the
methods available
and their parameters.
- See Also: Web Service