| Lesson 11 | URLs |
| Objective | Describe the functions, components, and types of URLs. |
A URL, or Uniform Resource Locator, specifies a unique address to a resource on the Internet. A resource can be a specific Web page, a
document, or an image. URLs are occasionally called URIs, or Uniform Resource Identifiers.
Parts of a URL
Delimiters separate the parts of a URL address. The first part of a URL indicates which protocol to use; the second part specifies
where the resource is located.
The difference between a URL and a Domain Name
This can be a confusing point, but it's an important one. In a nutshell, using the Internet address http://www.ggg.com, the Domain
Name is ggg.com, everything to the right of the http://www. The URL is everything including the http://www.ggg.com. You will be asked
many times in your future for just the domain when registering or searching for domains. Other times, you will be asked for the full
URL. It's important to know the difference between these terms!
Types of URLs
A URL describes the location of a specific file on a specific computer connected to the Internet. There are three types of URLs based
on where the files are located relative to the document. The table below describes the types of URLs and their general syntax.
Port numbers
There are two kinds of ports on a computer, hardware and software ports. Hardware ports identify a particular device. Software ports
identify the first instruction of a program used to handle common routines, such as a modem request. Ports are identified by a number
(possibly hexidecimal, so they may also contain letters).
You may recall in our URL MouseOver above, that software port numbers identify the sending and receiving application. Over the years, a PC or Macintosh have software ports that are typically assigned values of 256 or less. Ports numbered from 256 to1024 are assigned to services developed as part of the UNIX operating system. The table below identifies the port numbers for common Internet services. Recalling the port number in our MouseOver as 80, what service does this designate?
You may recall in our URL MouseOver above, that software port numbers identify the sending and receiving application. Over the years, a PC or Macintosh have software ports that are typically assigned values of 256 or less. Ports numbered from 256 to1024 are assigned to services developed as part of the UNIX operating system. The table below identifies the port numbers for common Internet services. Recalling the port number in our MouseOver as 80, what service does this designate?
Click the link below to review what you have learned about port numbers related to common Internet services. Internet Services Port Numbers
