Such window managers are generally very memory and CPU intensive, though they may be configurable to run reasonably well on lower-end systems. Minimalist is a window manager that provides only the most basic functions such as window placement, icons, and menus. These window managers are designed for systems where a windowing environment is required but every bit of memory and CPU cycle are expected to be available to applications, not sucked dry by the window manager. Since a desktop environment doesn't necessarily define which window manager to use, many window managers can be used in conjunction with either one or both environments. A virtual workspace allows you to keep applications running off-screen and bounce back and forth without necessarily having to iconize the application.
Pages can be page oriented or workspace oriented.
Workspace oriented is more sophisticated. These pagers allow you to have multiple pages in multiple workspaces. These are like having pages in a notebook, and then having multiple notebooks. Not all window managers provide panels. Some window managers that do not use panels offer other means of launching applications.