Please Whitelist This Site?

I know everyone hates ads. But please understand that I am providing premium content for free that takes hundreds of hours of time to research and write. I don't want to go to a pay-only model like some sites, but when more and more people block ads, I end up working for free. And I have a family to support, just like you. :)

If you like The TCP/IP Guide, please consider the download version. It's priced very economically and you can read all of it in a convenient format without ads.

If you want to use this site for free, I'd be grateful if you could add the site to the whitelist for Adblock. To do so, just open the Adblock menu and select "Disable on tcpipguide.com". Or go to the Tools menu and select "Adblock Plus Preferences...". Then click "Add Filter..." at the bottom, and add this string: "@@||tcpipguide.com^$document". Then just click OK.

Thanks for your understanding!

Sincerely, Charles Kozierok
Author and Publisher, The TCP/IP Guide


NOTE: Using software to mass-download the site degrades the server and is prohibited.
If you want to read The TCP/IP Guide offline, please consider licensing it. Thank you.

The Book is Here... and Now On Sale!

Searchable, convenient, complete TCP/IP information.
The TCP/IP Guide

Custom Search







Table Of Contents  The TCP/IP Guide
 9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)
      9  TCP/IP Key Applications and Application Protocols
           9  TCP/IP Application Layer Addressing: Uniform Resource Identifiers, Locators and Names (URIs, URLs and URNs)
                9  Uniform Resource Locators (URLs)

Previous Topic/Section
Uniform Resource Locators (URLs)
Previous Page
Pages in Current Topic/Section
1
234
Next Page
URL Schemes (Applications / Access Methods) and Scheme-Specific Syntaxes
Next Topic/Section

URL General Syntax
(Page 1 of 4)

Uniform Resource Locators (URLs) are a subset of Uniform Resource Identifiers (URIs) that consist of two components that identify how to access a resource on a TCP/IP internetwork. These two components are the location of the resource, and the method to be used to access it. These two pieces of information, taken together, allow a user with the appropriate software to obtain, read or otherwise work with many different kinds of resources such as files, objects, programs and much more.

The most general form of syntax for a URL contains only two elements, which correspond to the two pieces of information just described:

<scheme>:<scheme-specific-part>

The term scheme refers to a type of access method, which describes the way that the resource is to be used; it usually refers to either an application protocol, such as “http” or “ftp”, or a resource type such as “file”. A scheme name must contain only letters, plus signs (“+”), periods (“.”) and hyphens (“-”). In practice, they usually contain only letters. Schemes are case-insensitive but usually expressed in lower case.

The rest of the URL after the scheme (and the required colon separator) is scheme-specific. This is necessary because various protocols and access methods require different types and quantities of information to identify a particular resource. When a URL is read, the scheme name tells the program parsing it how to interpret the syntax of the rest of the URL.

Key Concept: Uniform Resource Locators (URLs) are the most widely-used type of URI. In its most basic form, a URL consists of two elements: a scheme that defines the protocol or other mechanism for accessing the resource, and a scheme-specific part that contains information that identifies the specific resource and indicates how it should be used. Some schemes use a common syntax for their scheme-specific parts, while others use a syntax unique to the scheme.



Previous Topic/Section
Uniform Resource Locators (URLs)
Previous Page
Pages in Current Topic/Section
1
234
Next Page
URL Schemes (Applications / Access Methods) and Scheme-Specific Syntaxes
Next Topic/Section

If you find The TCP/IP Guide useful, please consider making a small Paypal donation to help the site, using one of the buttons below. You can also donate a custom amount using the far right button (not less than $1 please, or PayPal gets most/all of your money!) In lieu of a larger donation, you may wish to consider purchasing a download license of The TCP/IP Guide. Thanks for your support!
Donate $2
Donate $5
Donate $10
Donate $20
Donate $30
Donate: $



Home - Table Of Contents - Contact Us

The TCP/IP Guide (http://www.TCPIPGuide.com)
Version 3.0 - Version Date: September 20, 2005

Copyright 2001-2005 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.