Memory
RAM - Random Access Memory A memory chip will have a size which is normally given in either mega or giga bytes.
Memory is then split up into a lot of storage blocks. The number of available blocks is governed by the size of the memory
Each block is numbered. This will start at 0 and go up in fixed sizes until it gets to the end. A memory chip will have a lot of memory blocks!
For example a 1GB memory chip will contain about 270'000'000 memory blocks
RAM is volatile, has high access speeds and is used to store data/ information needed by currently running programmes. It is also quite expensive depending on what type you get (EG. DDR, DDR2 or DDR3)

In computing, a memory address is a way of accessing data, by assigning unique 'addressses' (characters) to each block of space in the computers RAM memory. This means the data can be accessed by the computer.

RAM is volatile, meaning if your machine loses power, the content is wiped (unless you've saved it). Eg. A 'Microsoft Word'' document, will lose all it's data unless you kit 'Ctrl + S' (or manually save the file)

ROM - Read Only Memory
Your computer also has ROM, which (normally) cannot be overwritten. Without it, your computer will not boot (power on) correctly.
If you remove the power from your machine, the ROM will not be affected.

Read-only memory (ROM) is a class of storage medium used in computers and other electronic devices.

Flash Memory
Flash memory, is SSD (Solid State Device). This means, if you take away power from it, it will not damage any data or the drive itself. It stores the data in portable electronics, eg. Mobiles phones, USBs, etc.

Flash memory is a solid-state chip that maintains stored data without any external power source. It is commonly used in portable electronics and removable storage devices, and to replace computer hard drives.

Backing storage
In reference to computer storage, backing storage is any device, or medium, that computer data can be stored on and is typically non-volatile. Common types of backing storage devices or medium are hard drives, floppy disks, CD or DVD discs, memory sticks, and magnetic tapes.

	Created by ca.loizou about 11 years ago

Notes about memory types