VNC stands for Virtual Network Computing. It is, in essence, a remote display system which allows you to view a computing `desktop' environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures.
This package provides a server to which X clients can connect and the server generates a display that can be viewed with a vncviewer.
The difference between the tightvncserver and the normal vncserver is the data encoding, optimized for low bandwidth connections. If the client do not support jpeg or zlib encoding it can use the default one. Later versions of vncserver (> 3.3.3r2) support a new automatic encoding that should be equally good as the tightvnc encoding.
Note: This server does not support or need a display. You need a vncviewer to see something. However, this viewer may also be on a computer running other operating systems in the local net.