The echo command is used to display part of the SSI "environment".

Common uses for echo are :

1. Display the current date and time.
     - shows how to display and format the host server's date and time.

2. Display the last modified date of a web page.
     - shows how to display the last date a specific web page was changed.

3. Create a "back" button.
     - does anyone really need this? Same as the browser BACK button on the tool bar.

4. Other uses.
     - other things echo can display.

Pay very close attention to symbols, spaces, and CaPiTaLiZaTiOn. SSI can be a very picky coding.