1. Windows 98 includes a core composed of three components ? User, Kernel, and Graphics Device Interface (GDI).
a. USER - Manages input from the keyboard, mouse, and other input devices and output to the user interface (windows, icons, menus, and so on). It also manages interaction with the sound driver, timer, and communications ports.
b. KERNEL:
(1) Provides base operating system functionality, including file I/O services, virtual memory management, and task scheduling.
(2) Exception handling is another service of the Kernel. Exceptions are events that occur as a program runs and that require software outside the normal flow of control to be run.
(3) Allocates virtual memory, resolves import references, and supports demand paging for the application. As the application runs, the Kernel schedules and runs threads of each process owned by an application.
(4) Provides services to both 16-bit and 32-bit applications by using a translation process called thunking to map between 16-bit and 32-bit formats. Thunking converts a 16-bit value to its 32-bit equivalent.
2. GDI - is the graphical system that manages what appears on the screen. It also provides graphics support for printers and other output devices. It draws graphic primitives, manipulates bitmaps, and interacts with device-independent graphics drivers, including those for display and printer output device drivers.