The base distribution currently consists of eleven packages. Some are required, while others are optional. Each package is available in each of the aforementioned package formats.
(RECOMMENDED)
This package contains support libraries that have not been written as part of the KDE project, but are needed nevertheless. If you already have the libraries (libgif, libjpeg, libmime, libuu, libgdbm) in this package in the required versions, then you do not need to install this package. When in doubt, install it. Note that for the Debian packages, this package is required.
(REQUIRED)
This package contains shared libraries that are needed by all KDE applications.
(REQUIRED)
This package contains the base applications that form the core of the K Desktop Environment like the window manager, the terminal emulator, the control center, the file manager and the panel.
(OPTIONAL)
Various games like mahjongg, snake, asteroids and tetris.
(OPTIONAL)
Various graphics-related programs like PostScript[TM] previewer, dvi previewer and a drawing program.
(OPTIONAL)
Various desktop tools like a calculator, an editor and other nifty stuff.
(OPTIONAL)
Multimedia applications like a CD player and a mixer.
(OPTIONAL)
Internet applications. Currently contains the mail program, the news reader and several other network-related programs.
(OPTIONAL)
System administration programs. Currently contains the user manager and the System V runlevel editor.
(OPTIONAL)
Toys!
(OPTIONAL)
Your desktop would never be complete without an organizer, right?
kdesupport (if needed) should be installed before everything else. The next (or first) package should be kdelibs. The other packages can be installed in any arbitrary order.