Uniform resource identifier (URI) and URL
Students will be expected to not only define, but also discuss the characteristics of URL and URI. Students will also be expected to describe the purpose of a URL.
Characteristics of a URI[edit]
A Uniform Resource Locator (URL), is a reference to a web resource that specifies its location on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identifier (URI).[2]
- URL's have different parts. Every URL MUST have:
- scheme and host
- URL's have different parts. Every URL MIGHT have:
- user information
- port
- query
- fragment
Please click here for an example of these different parts. In your normal day-to-day use, you probably only use a scheme and a host.
Please click here to see a list of all the available schemes. There's a LOT more than HTTP and HTTPS!!
Example of a URL[edit]
The following figure displays two example URIs and their component parts. [3]
hierarchical part
┌───────────────────┴─────────────────────┐
authority path
┌───────────────┴───────────────┐┌───┴────┐
abc://username:password@example.com:123/path/data?key=value&key2=value2#fragid1
└┬┘ └───────┬───────┘ └────┬────┘ └┬┘ └─────────┬─────────┘ └──┬──┘
scheme user information host port query fragment
urn:example:mammal:monotreme:echidna
└┬┘ └──────────────┬───────────────┘
scheme path
Purpose of a URL[edit]
A URL is a string of characters used to identify a resource. The purpose of a URL is to easily retrieve network resources. URL's also make linking to resources easier.
Do you understand this?[edit]
- identify each part of this URI:
file:///Users/billdagjana/Desktop/
- Which one of these does a URI NOT do:
- Enable easier access to resources
- Provide excellent resources for linking between resources
- Allow you to more quickly download content
- Provide a unified syntax to access remote resources
Standards[edit]
These standards are used from the IB Computer Science Subject Guide[4]
- Identify the characteristics of a uniform resource identifier (URI) URL.
- Describe the purpose of a URL.
References[edit]
- ↑ http://www.flaticon.com/
- ↑ https://en.wikipedia.org/wiki/URL
- ↑ https://en.wikipedia.org/wiki/Uniform_Resource_Identifier#Examples
- ↑ IB Diploma Programme Computer science guide (first examinations 2014). Cardiff, Wales, United Kingdom: International Baccalaureate Organization. January 2012.