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.
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.
This can be a confusing point, but it is an important one. In a nutshell, using the Internet address https://www.cplusoop.com/, the Domain Name is cplusoop.com,
everything to the right of the
http://www.
The URL is everything including the https://www.cplusoop.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 is important to understand the difference between these terms.
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.
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?