Cosma / Communication / Media / Storage / Hardware / Memory




memory : a device (as a chip) or a component of a device in which information especially for a computer can be inserted and stored and from which it may be extracted when wanted — Webster   See also OneLook

FOLDOC: Free Online Dictionary of Computing


Glossary of Computer and Internet Terms (


Memory refers to the computer hardware devices used to store information for immediate use in a computer; it is synonymous with the term “primary storage”. Computer memory operates at a high speed, for example random-access memory (RAM), as a distinction from storage that provides slow-to-access program and data storage but offers higher capacities. If needed, contents of the computer memory can be transferred to secondary storage, through a memory management technique called “virtual memory”. An archaic synonym for memory is store.

The term “memory”, meaning “primary storage” or “main memory”, is often associated with addressable semiconductor memory, i.e. integrated circuits consisting of silicon-based transistors, used for example as primary storage but also other purposes in computers and other digital electronic devices. There are two main kinds of semiconductor memory, volatile and non-volatile. Examples of non-volatile memory are flash memory (used as secondary memory) and ROM, PROM, EPROM and EEPROM memory (used for storing firmware such as BIOS). Examples of volatile memory are primary storage, which is typically dynamic random-access memory (DRAM), and fast CPU cache memory, which is typically static random-access memory (SRAM) that is fast but energy-consuming, offering lower memory areal density than DRAM.

Most semiconductor memory is organized into memory cells or bistable flip-flops, each storing one bit (0 or 1). Flash memory organization includes both one bit per memory cell and multiple bits per cell (called MLC, Multiple Level Cell). The memory cells are grouped into words of fixed word length, for example 1, 2, 4, 8, 16, 32, 64 or 128 bit. Each word can be accessed by a binary address of N bit, making it possible to store 2 raised by N words in the memory. This implies that processor registers normally are not considered as memory, since they only store one word and do not include an addressing mechanism.

Typical secondary storage devices are hard disk drives and solid-state drives. — Wikipedia

Computer Memory (Encyclopædia Britannica)




Memory Upgrade, How to.. (Computer Memory Upgrade)
Computer Memory (Computer Memory Upgrade)




The Punched Card Tabulator (IBM)
Punched Cards: From Math to Data (Computer History Museum)
Punched Card (Wikipedia)

Punched Tape (Wikipedia)

Paper data storage (Wikipedia)
Computerphile (YouTube Channel)


Museum of Obsolete Objects (YouTube channel)

Revolution: The First 2000 Years of Computing: Memory & Storage (Computer History Museum)
Timeline of Computer History: Memory and Storage (Computer History Museum)

Data Formats Timeline (Jason Curtis, Museum Of Obsolete Media)


WorldCat, Library of Congress, UPenn Online Books, Open Library




MERLOT: Multimedia Educational Resource for Learning and Online Teaching
OER Commons: Open Educational Resources


Crash Course: Computer Science (YouTube Channel)



Data / Storage And Retrieval (Communications of the ACM)
Memory News (IEEE Spectrum)










A kilobyte rewritable atomic memory (Nature Nanotechnology)
Nanoscale Memory (Franz Himpsel, U. Wisconsin)



Communications of the ACM: Data / Storage And Retrieval The latest news, opinion and research in data / storage and retrieval, from Communications online.

  • Digital Synergy
    on June 1, 2022 at 4:00 am

    Inventing an imaginary company helped me imagine how powerful it can be to have data available that permits fact-based analysis of business performance, projections for future business operations, and understanding of the marketplace the business serves.

  • Addressing Labor Shortages with Automation
    on June 1, 2022 at 4:00 am

    Labor shortages have many companies turning to automation technology, but with mixed outcomes.

  • Immersion Cooling Heats Up
    on June 1, 2022 at 4:00 am

    Depending on climate conditions, the availability of renewables and other factors, immersion cooling can make a profound difference in both energy consumption and costs.

  • The Planning and Care of Data
    on June 1, 2022 at 4:00 am

    Rearranging buckets for no good reason.

  • Responsible Data Management
    on June 1, 2022 at 4:00 am

    Perspectives on the role and responsibility of the data-management research community in designing, developing, using, and overseeing automated decision systems.




Here are links to pages about closely related subjects.


Function Communications Computation Storage Creation Simulation
Analog Mail Device Paper Type, Print Automaton
Electronic Network Calculator Tape Record Elektro
Digital Internet Computer
Hardware Modem Microprocessor Memory Peripheral Robot, XR
Software Service (Web) Program (OS, SS) Database Application AI, VW

Format Multimedia (Video, Animation) Image (Object) Scent, Flavor, Audio (Text) Haptic, “Other



1.   The resources on this page are are organized by a classification scheme developed exclusively for Cosma.