The Terminal is a tool in the Applications>Utilities folder, used to perform various tasks. Many of the commands and functions available at the command prompt in Terminal can only be achieved there. It can do things that are not possible with the mouse, menus and buttons.
If you have ever used it, you will know that it looks very dull. However, the default black text on a white background is easily changed and you can customise the built-in themes, called profiles. You can change the colours, choose a more interesting font, add a great background image, and even make the window see-through.
Customise a profile