Non-volatileNon-volatile memory, nonvolatile memory, NVM or non-volatile storage, is computer memory that can retain the stored information even when not powered. Examples of non-volatile memory include read-only memory, flash memory, most types of magnetic computer storage devices (e.g. hard disks, floppy disk drives, and magnetic tape), optical disc drives, and early computer storage methods ...Non-volatile random access memoryRandom access memory (usually known by its acronym, RAM) is a type of data storage used in computers. 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. The word "random" refers to the fact that any piece of data can be returned in a constant time, regardless of its physical location and whether or not it is related to the previous ...random access memory (NVRAM) is the general name used to describe any type of random access memory which does not lose its information when power is turned off. This is in contrast to the most common forms of random access memory today, DRAMNo quick definition available. DRAM and SRAMStatic random access memory (SRAM) is a type of semiconductor memory. The word "static" indicates that the memory retains its contents as long as power remains applied, unlike dynamic RAM (DRAM) that needs to be periodically refreshed (nevertheless, SRAM should not be confused with ...SRAM, which both require continual power in order to maintain their data. NVRAM is a subgroup of the more general class of non-volatile memory types, the difference being that NVRAM devices offer random accessIn computer science, random access is the ability to access an arbitrary element of a sequence in equal time. The opposite is sequential access, where a remote element takes longer time to access. A typical illustration of this distinction is the ancient scroll (sequential) and the book where any random page can be flipped open immediately. A more modern example is a cassette tape (sequential—you have to fast-forward ...random access, as opposed to sequential accessIn computer science, sequential access means that a group of elements (e.g. data in a memory array or a disk file or on a tape) is accessed in a predetermined, ordered sequence. Sequential access is sometimes the only way of accessing the data, for example if it is on a tape. It may also be the access method of choice, for example if we simply want to process a sequence of data elements in order. In data structures, a data structure is said to have sequential access if one can only visit ...sequential access like hard disksA hard disk drive (HDD), commonly referred to as a hard drive or hard disk,Other terms used to describe hard disk drives include, disk drive, disk file, DASD (Direct Access Storage Device), fixed disk, CKD disk and Winchester Disk Drive. is a non-volatile storage device which stores digitally encoded data on rapidly rotating platters with magnetic surfaces. Strictly speaking, "drive" refers to a device distinct from its medium, such as a tape drive and its tape, or a floppy disk drive ...hard disks.
The best-known form of NVRAM memory today is flash memoryFlash memory is non-volatile computer memory that can be electrically erased and reprogrammed. It is a technology that is primarily used in memory cards, USB flash drives (thumb drives, handy drive, memory stick, flash stick, jump drive), which are used for general storage and transfer of data between computers and other digital products. It is a specific type of EEPROM that is erased and programmed ...flash memory. Some claim flash memory to be a truly "universal memory", offering the performance of the best SRAM devices with the non-volatility of Flash. To date these alternatives have not yet become mainstream.
