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Uniform Resource Locator
A Uniform Resource Locator (URL) is a Uniform Resource Identifier (URI) that specifies where an identified resource is available and the mechanism for retrieving it.
The URL is set of 4 numbers separated by periods.
Eg: 72.14.207.99 [ Google IP address ]
URL is represented as a string that explains full location of resource on the internet.
A specific website can be accessed by typing its URL in the address bar of the browser
Syntax of URL
1. Scheme name [ Protocol ]
2. Domain name
3. Port number
4. Resource path
5. Query string [ for programs such as Common Gateway Interface (CGI) scripts ]
6. fragment identifier ( Optional )
Scheme name [ Protocol ]
The scheme name defines the namespace, purpose, and the syntax of the remaining part of the URL.
Browser will try to process a URL according to its scheme and context.
For example http://example.org:80
Other examples of scheme names include https:, gopher:, wais:, ftp:.
Domain name
The domain name or IP address gives the destination location for the URL.
The domain name portion of a URL is case-insensitive
Eg: WWW.GOOGLE.COM / google.com
Domain type
com: specifies commercial entities
net: highlights network
org: organizations
edu: colleges and universities
gov: government organization
mil: military entities of USA
Local domains
in: India
cu: Cuba
uk: United Kingdom
cn: China
dk: Denmark
Port number
The port number is optional.
if omitted, the default for the scheme is used.
The default port for an http: request is 80.
The default port for an https: request is 443.
Path
The path is used to specify and find the resource requested.
It is case-sensitive.
Eg: http://wonderclipartsbirthday /birthday_graphics_30.gif&imgrefur

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NISM
Domain name
It is an identification label that defines a realm of administrative autonomy, authority, or control in the Internet.
Domain names are hostnames that identify Internet Protocol (IP) resources such as web sites.
Domain names are formed by the rules and procedures of the Domain Name System (DNS)
NISM
Domain name levels
They are organized in subordinate levels (subdomains) of the DNS root domain, which is nameless.
The first-level set of domain names are the top-level domains (TLDs), including the generic top-level domains (gTLDs), such as the prominent domains com, net and org, and the country code top-level domains (ccTLDs).
Below these top-level domains in the DNS hierarchy are the second-level and third-level domain names that are typically open for reservation by end-users that wish to connect local area networks to the Internet, create other publicly accessible Internet resources or run web sites.