As with anything known to man, computers are not without their quirks. Sometimes it seems that computers almost plan to confuse and frustrate users, as there are so many things that could be creating the strange behavior we see. Add to that the multiple forms of memory and the behaviors of each, which can choose to exhibit some pretty weird and unwanted behavior at inopportune times, and you’ve got the mix for a thoroughly confusing experience.
However, there is no need to panic. Computer memory has a class of characteristics that are unique and can help us better understand why it sometimes acts the way it does. These characteristics consist of volatility, mutability, accessibility, and addressability. Add capacity and performance, and the combination isn’t that hard to crack. Armed with this knowledge, we can understand computer memory and help make it work better for us.
Here are some terms to understand before deciding that the computer is acting strange and needs to be replaced. Usually the computer’s tendency to eat our documents and torment us with inoperable operations is just the fault of not understanding the capabilities of memory types or that there is more than one type even among the named memories we know of, like RAM and ROM.
Volatility has two poles: what is volatile and what is not. The only difference is what the memory can do if there is a power outage to the computer. Non-volatile memory will retain our work even without power. This type of memory strives to make us happy by saving our work and favorite computer programs for later use.
Volatile memory would be called temperamental when compared to how we work ourselves. Another way to view this type of memory is to think of it as the emotions of the computer. Just as we are fickle in our emotions, so are computers. This type of memory must have a constant power supply so as not to retain your work. If the power fades, so does the volatile memory. He likes a good load.
Dynamic and static forms of memory are generally associated with RAM. Both forms are volatile and require a constant power source, but dynamic memory is periodically updated. Static memory is not updated, which makes it a useful option, but not as popular as dynamic memory.
Mutability is the ability of computer memory to read from and write to storage and comes in the form of immutable and mutable memory types. Mutable storage can be overwritten more than once and is necessary for a computer to be useful for many of the tasks that users want to do with the computer. This type of memory is used for both primary and secondary storage purposes. Specific types of storage and mutable memory include ROM.
Accessibility is found in both random access forms and sequential forms. Random Access is probably the best known and is affectionately called RAM. This means that storage in any location can be accessed in roughly the same amount of time, which seems instantaneous to us, but really isn’t.
Sequential memory is slower and information is collected and accessed in serial order. Typically, this type can be commonly seen with offline storage.
Addressability comes in three forms: location, file, and content. The location is done by a numeric memory address which is usually limited to primary storage and is accessed internally. The file is made by human readable filenames. In other words, the name you gave a file is how it is addressed. Content addressability refers to a selected hash value: a short identifier with a number pointing to the memory address for the information.
Now that the terms aren’t so mysterious, it will be easier to understand some of the memory-related behaviors your computer displays. This should make using your computer a more pleasant experience.