Computer Memory:

Computer memory is used to hold binary strings of data destined to manipulate by the CPU.

Memory used by the processor to update its registers and associated data-cells. Processor forwards the data in memory then send out to the specific output device's block.

Sometimes it is easy to say that memory works like a classroom. Where students came in class for learning, the classroom is the learning area.

Every-thing stored in memory is just a number; the interpretation of each number depends on the program that owns the information.

The number stored in individual bytes in memory range from 0 to 255 (which is what can be represented by the 8 bits in each byte). That's not enough to do everything you use a computer for. If the computer has to remember that you have thousands of paper clips in inventory, it has to store that number in at least two memory locations. Most PC processors are designed to operate on 4 bytes (32 bits) at a time, so programs for those processors store most numbers as 32-bit values. If the first byte holding your paper clip inventory is at address 102916, locations 102916 through 102919 hold the entire number. The same idea is true for instructions, which can require 1, 2 or more bytes to hold. Any time the processor references the first byte of a number of instruction, it references all of them.

 Memory Controller Chips:

 Every computer has within it a hardware logic circuit called the memory controller. This is the part of the system that, well, controls the memory. It generates the necessary signals to control the reading and writing of information from and to the memory, and interfaces the memory with the other major parts of the system. The memory controller is normally integrated into the system chipset.

Your computer uses memory modules made from several memory chips. It's built that way because memory chips themselves are commonly only a few bits wide. The memory module operates the individual chips in parallel.

 The key parameters defining a memory module are these:

 Capacity:

A memory module holds a specified number of bytes, with one address corresponding to each byte. The capacity of a memory module is the number of bytes it holds.

 Width:

A memory module built from multiple chips in parallel can be as wide the module designer wants, with the width being the number of bits that the memory accesses at one time.

Memory is a collection of places to store numbers. Each place, called a memory location, is one byte. One memory location stores one value.

That value can be anything in the range of 0 to 255. Each memory location stores a physically different number, although the same value can be stored in different locations any number of times.

Every memory location has an address, which is a unique number assigned to it and on other location.

When the processor wants to read or write the value in a specific location, it tells the memory the address of the location. Addresses usually start at zero and continue up from there.