(i)  There are two types of accessing methods to access (read and write) the memory.
(ii) They are sequential access and random access. In sequential access, the memory is accessed an orderly manner from starting to end.
(iii) But, in random access, any byte of memory can be accessed directly without navigating through previous bytes.

(i) CISC stands for Complex Instruction Set Computers.
(ii) They support hundreds of instructions. Computers supporting CISC can accomplish a wide variety of tasks, making them ideal for personal computers.
(iii) Examples of CISC processors are Intel 386 & 480 Pentium, Pentium II and Ill, and Motorola 68000

(i) RISC stands for Reduced Instruction Set Computers. They have a small set of highly optimized instructions.
(ii) Complex instructions are also implemented using simpler instructions, thus reducing the size of the instruction set.
(iii) Examples of RISC processors are Intel P6, Pentium IV, AMD K6 and K7.

(i) The address bus is used to point a memory location.
(ii) A decoder, a digital circuit is used to point to the specific memory location where the word can be located.
(iii) The address register is connected with the address bus, which provides the address of the instruction.
(iv) A data bus is used to transfer data between the memory and the CPU.
(v) The data bus is bidirectional and the address bus is unidirectional.
(vi) The control bus controls both read and write operations.
(vii) The system bus is a bunch of wires which is the collection of address bus, data bus and control bus that serves as communication channels between the microprocessor and other devices.

Word size determines the amount of RAM that can be accessed by a at one time and the total number of pins on the microprocessor. Total number of input and output pins in turn determines the architecture of the microprocessor.