Word Size: The “natural”, most efficient size to copy to and from memory. Usually corresponds to the size of the general purpose registers.
Address Size: The number of bits used for each address. Usually the same as the size of the general purpose registers.
Processors vs. Cores: A system can have multiple CPU’s. In the last decade, multi-processor systems have become common with multi-core chips, in which more than one independent execution unit is placed in the same CPU package. A new PC today has typically 2 to 4 cores, and the number of cores is expected to rise in the next few decades.
Boot Firmware: The code which the CPU runs upon power on. This code usually resides in a ROM chip on the motherboard, from which the CPU is hardwired to read its first instructions. On PC’s, this chip is called the BIOS (Basic Input/Ouput System). The principle job of boot firmware is to begin the loading of the operating system, which usually resides on a hard drive.
