In html,

  a GLOBAL reference
assumes NOTHING!!!
(url must include full URL address; starting with protocol.)

<a href="http://hive.sewanee.edu/ldale/284/xxx.html"> A Global Ref Link </a>

(refers to page on hive server, in a folder called ldale, in a subfolder called 284, file is named xxx.html)

  NOTICE, there are NO SPACES BETWEEN THE DOUBLE QUOTES. 
  PARTS:

                   http   - HyperText Transfer Protocol 
                   ://    - separates protocol from server name; note THERE MUST BE TWO slashes

       hive.sewanee.edu   - server

                  ldale   - a username on hive (really a folder in root of hive's doctree)
                              This is your html folder! Files outside of these username folders 
                              CANNOT be globally referenced.

                   284    - must be a subfolder of ldale's html folder
              xxx.html    - must be the exact name of a file that exists in 284 folder
A Global Ref Link

  a LOCAL/RELATIVE reference
assumes file is 'nearby'
(Same server. url only contains 'directions' relative to current page location.)

<a href="theOtherPage.html"> Local Reference Link </a>

(refers to file the same folder on the same server!)

  NOTICE, there are NO SPACES BETWEEN THE DOUBLE QUOTES. 
  PARTS:

       <> - tells browser this is meta information that will be used to control
                 appearance or provide instructions for how to find other resources
                 like pages, images, video, etc.

       a     - html opening tag called 'anchor'
       href  - indicated 'hypermedia reference' 
       /a    - html closing tag for 'anchor'
Local Reference Link

 

Why does this matter so much?

Because...this thinking is ubiquitous. 

   Unix operating system - Linux is a "flavor" of Unix

   "folders" are "directories"

   "subfolders" are "subdirectories"

   This can all be modeled and should be envisioned as a TREE
ls command line way to list directory contents
ls *.java list all files with names that end in characters ".java"
ls ../*.java list all files with names that end in characters ".java" in the parent directory
ls ../../*.java list all files with names that end in characters ".java" in the parent's parent directory
pwd print working directory

How would you expect questions testing your understanding of the hierarchical nature of directory structure to be presented on a quiz?