The organization name is critical. Gopher is an older protocol that groups and links documents together. Telnet is for establishing a computer session with a host computer. It usually requires a login. Ftp is File Transfer Protocol and is usually used for downloading files.
News is for discussion groups.
You can read articles and notes sent my others and respond to them for all to read. Mailto is a method for sending electronic mail to others. Links can also be made to graphics files that are embedded in the web pages themselves. The browser usually underlines and colors the anchors so you can tell where there is a link to another web page. As you go from page to page, you can save references to the interesting ones by saving the URLs as bookmarks.