Often times non-techies out there have failed to recognize the difference between memory and hard drive space. A message popping up saying they are running out of memory and they may try emptying the recycle bin, clearing the cache of their browser, and maybe even running a Defrag in attempts to clear the error from taking place again. Any techie will immediately know memory and hard drive space are however two separate elements to the computer. While those actions may help free up space for storage; they have almost no real impact on the memory of the system.
In an effort to explain the difference between the two, we can actually use your own brain as an example. Right now as you read this article, it is in essence being loaded to your 'memory' or if you are a computer, your RAM. Elements or possibly even the entire article (should you be lucky enough to have a photographic memory) may hold some information worthy of retention. As your mind makes that connection and works to retain that data, the information is moved from the memory portion of your brain, to the storage; or in terms of the computer from RAM to the hard disk drive. From storage it is then retained until called upon, at which point it will again surface to your memory, or RAM for recollection or changes to be made. Once the information has served its purpose, if it is again to be remembered and not forgotten, to the storage it returns until called upon again.
The computer as this example shows, works very much within this methodology. Granted data that is called from storage to RAM is typically copied from the storage side to the RAM for handling so that should power be lost the original unchanged data remains present on the hard drive in-tact; this is actually something that was not always the case; prior to auto-save and many other insuring actions taking place in the background of the modern computer. Today there is minimal fear if/when your computer should reboot in the middle of working with a document that the entire document has been obliterated along with the power to the PC. There was indeed a time when data from storage was not replicated to RAM but was actually moved there for handling. Many networking devices such as routers and smart switches can still have such volatile handlings when working with their configuration files. Granted that's not to say if you had a programmed router and rebooted it while in use you are assured all the programming in that router is lost; but if you were in the process of programming the router or switch prior to saving your work, the changes you had applied before that power cycling would definitely be lost.
So while a message such as 'low memory' might instigate a cleanup from an end-user of their hard drive and thusly storage on that machine; this will likely have little to no affect on bringing such messages to an end. Additional RAM would seem a worthy option, but in most cases a message regarding low memory, could be due to any number of programs running in the background eating up memory resources and limiting the capacity available. The only affect cleaning the hard disk may contribute to resolving this issue is the fact that Windows and other operating systems will often make use of a portion of the hard drive as a swap for memory. That is to say part of the drive is being used like RAM within the computer and thusly there is a chance that such actions could inhibit these messages from popping up again unless or until the resources are again lacking.
The key thing to understand and recognize is although it does take 'memory' to store information, it isn't stored in RAM it is stored to the hard drive. RAM is literally what is being seen and dealt with in the here and now, while the hard drive is where information that is retained gets stored. So if you want more space to store your pictures and videos, you want either another hard drive or a larger one; if your computer is typically running slow when playing games or loading web-pages, additional RAM could speed things up. While in many cases when it comes to 'low memory' messages; it may not be a hardware deficiency at all, perhaps you have too many programs open and running while doing what you are trying to accomplish, or worse it could even be a malware, spyware, or virus hiding in your RAM eating resources. While there are always more clues required to piece the puzzle of a computer problem together, having a clear understanding of the difference between memory, RAM, and hard drive space can definitely help when explaining to a technician attempting to bring that remedy.