ROM is usually very small in size and contains a program, a section of BIOS, with the
sole task of starting up the system. The startup process is called bootstrapping because
the system is effectively pulling itself up by its bootstraps. This program in ROM initializes
the computer. It also retrieves the rest of the resident portion of the operating
system from secondary storage and loads it into RAM.
RAM is the part of main memory where programs are loaded and executed. The RAM
layout for a computer with 1 MB of memory is given in Figure 14.3.