Storage and Storage Devices

All computers take raw data, process that data, and then covert that data to some type of output.  That output could be printed, it could be displayed on a monitor, or it could be saved to some type of storage device.  This cycle is called the IPO cycle.  IPO is an abbreviation for Input, Processing, Output.  What goes into the computer is called data.  After the data has been processed it is called information.

IPO Input Process Output cycle
Your computer doesn’t work directly with data stored on your storage devices such as your hard drive or your USB drive rather it takes the data from your drives when it needs it to work on . and loads it into RAM. (random access memory). RAM is also called primary storage or main memory. RAM is volatile memory, which means that it is temporary. When you turn your computer off or it loses power for some reason all the data in RAM is lost. Memory on your drives is non-volatile. When your computer shuts off the data on your drives remain. Memory on your drives is called secondary storage.

Let’s say that you open a document named Sales in Microsoft Word. Your computer loads the file from the hard drive into RAM. When the data needs processing it is moved into the CPU. After the CPU has performed all necessary processing on it the data is moved back into RAM. When you click the Save button in Word the file is updated on the hard drive. If you exit Word before saving your file or if you lose power, any changes you made to the Sales document will be lost because the file on the drive hasn’t been updated.