When I was young, memory and RAM were the same, but now they seems to be different (this is called progress).
But what exactly is the difference in modern smartphones?
What is (free) RAM and when is (free) RAM important?
How can I help it as a user?
When I was young, memory and RAM were the same, but now they seems to be different (this is called progress).
But what exactly is the difference in modern smartphones?
What is (free) RAM and when is (free) RAM important?
How can I help it as a user?
What is the difference exactly in modern smartphones?
In Computer Science, memory is a wide concept for everything that is capable of storing data, while RAM only stands for Random Access Memory, or more precisely, runtime memory.
Memory is the same word that the M stands for in both acronyms ROM and RAM. It's simply because both of them can store data, despite one being non-volatile and the other being volatile.
These concepts haven't changed even if you're talking about modern smartphones.
Fore more information, see Are there guidelines on how much free RAM a phone should have? and our tag wiki for ram
What is (free) RAM and when is (free) RAM important?
Whenever a process runs, it requires RAM to store is runtime data. When many processes run together, they demand more RAM. You should never make your phone's RAM full, so a portion of its RAM is available for use when a process requests more. That "available for use" RAM is called free RAM (or more precisely, "available RAM").
Free RAM is always important, but it is often more important when you're trying to start another app or running a resource-intensive app. It is because when there isn't enough RAM, some processes may fail, and resource-intensive apps will refuse to run.
How can I as a user help it?
If you're using a moderately new phone, leave it alone because Android can handle it very well. Stay away from "RAM cleaner"s and "Task Killer"s as they do no help actually.
If you're using an old phone with 256 MB or so of RAM running Android 2.x, you should install less apps and routinely terminate them, or throw it away and buy a new phone.
"Memory" is a vague term. It can refer to the RAM (the memory programs use while they're running) or to the storage (where things are saved). The storage is the equivalent of a hard disk on your PC, but it's not actually a hard disk, it's Flash memory.
You need free storage to install new apps or download music, videos, etc. If you run out of storage, you might need to free up some yourself by uninstalling apps or deleting downloaded files.
You need free RAM to run more apps, but this is managed by Android. When an app runs, it starts using RAM, but when you stop using it (back out of it, or switch to another app), Android doesn't remove it from RAM right away. This way, the app starts faster next time you run it, because it doesn't need to load everything from storage again. But when all the RAM is full, Android will remove apps that you haven't used in a while. Next time you start those apps, they'll be loaded from storage.
Normally you don't need to worry about how much free RAM you have, because Android manages it.