- Computer memory management is divided into three overlapping sections: hardware, operating systems and applications. Hardware memory management has to do with the electronic procedures that store data (such as random access memory and caches). Operating system memory management involves the allocation and recycling of memory resources to software programs. Applications memory management deals with supplying memory to data structures and objects with limited resources.
- RAM versus SAM. Random access memory (RAM) gets its name because it is possible to access memory cells directly by knowing the row and column of the intersecting cells. Serial access memory (SAM) is made of memory cells that can only be accessed in sequence. The main difference is that SAM stores data in the order in which it is used and RAM stores data in any order. In managing computer memory, DRAM (dynamic random access memory) uses a capacitor (electron bucket) and a transistor to create memory cells. These cells represent one bit (0 or 1) of data, which has to be refreshed constantly in order to remember what it is holding. If the computer "slows down," that is the memory refreshing process being used by the DRAM. It empties (to 0) and then fills back up again (to 1).
- Operating systems pretend the computer has more memory than what is available, then it recycles the virtual memory for reuse when programs no longer require it. There is no such thing as "too much" RAM in an OS (operating system), particularly with graphic-intensive programs and software. This is one case where more is definitely merrier. Different operating systems require different amounts of RAM, with the Linux OS being the least greedy of the better-known systems at a requirement of a mere 4 megabytes. The MAC OS X is the greediest at 512 megs. The Microsoft XP OS requires about 128 megabytes to run, but again, more is better in all cases.
- Application software programs cannot predict how much memory they are going to require until the program is actually being used. Applications combine allocation and recycling of memory. During allocation, memory is temporarily "blocked" to allow a program to run. When the blocks are no longer needed, they are recycled or re-allocated for use with other applications, or programs.
- Manual memory management is when the computer programmer or administrator has direct control over the recycling of memory. It has to be instructed to be recycled. With automatic memory management, the system is programmed to recycle blocks of memory without anyone having to code instructions.
