Storage
ROM
Bios stand for basic input/output system. BIOS refer to the firmware code run by a PC when turned on. The BIOS runs off the PROM, EPROM or flash memory. Nearly all BIOS implementations can optionally execute a setup program interfacing the non-volatile BIOS memory (CMOS). This memory holds user customisable configuration data (time, Date, Hard Drive details etc.) accessed by the BIOS code.
Secondary Storage
RAM
Random Access Memory is a type of data storage used in computers (main memory). It takes the form of integrated circuits that allow the stored data to be accessed in any order- that is, at random and without the physical movement of the storage medium or a physical reading head. Unlike ROM Ram is non-volatile allowing data to be deleted and changes where as ROM setting are non volatile which is set by the manufacturer.
CPU Cache
A CPU cache is used by the CPU to distribute latency between the memory and the CPU to reduce average time to access RAM. The cache store copies of data most frequently used by the main memory locations. As long as most memory accesses are to cached memory locations, the average latency of memory accesses will be closer to the cache latency than to the latency of main memory.
Hard Disk Drive
A HDD is a non volatile storage device which stores digitally encoded data on rapidly rotation platters with magnetic surfaces. Using actuators spindles and a reading/writing head the HDD stores data based on the speed of the platter rotating allowing fast access to storage.
