Computer memory can refer to many types of memory within a computer, but it generally refers to random access memory (RAM). It is physically located on computer chips embedded in the motherboard of the computer. RAM is electronic rather than mechanical; that is, it has no moving parts and therefore data access is very fast. Modern computers usually have between 256 MB (megabytes) and 2 GB (gigabytes) of RAM, although there are, of course, computers with more or less RAM. RAM is also volatile, meaning it is lost when the computer is turned off.
A computer motherboard.
The expensive nature of RAM prompted the creation of another type of computer memory called virtual memory. With virtual memory, you only notice a slowdown in performance when you try to run a program whose files are in virtual memory. Essentially, this slowdown is only seen when changing programs. In this way, virtual memory often offers a cheaper alternative to RAM.
A RAM card.
A third type of computer memory is cache memory. There are two types of cache. The main cache, or level 1 cache, is built into the central processing unit (CPU) and ensures the instant availability of frequently needed data by the CPU. The secondary cache, or level 2 cache, is usually built into a memory chip, located very close to the CPU, and has a direct connection to the CPU through dedicated circuitry. The secondary cache has a larger capacity than the primary cache. The cache basically speeds up the speed at which data is moved from main memory to the CPU.
A screenshot of the BIOS, a type of flash memory.
Registers form a fourth type of computer memory. These are units within the CPU that hold specific types of data, especially for the Arithmetic and Logic Unit (ALU). A final pool of computer memory is called flash. This is a type of solid state rewritable memory. Examples of flash memory include BIOS and memory cards. Like RAM, they are electronic, not mechanical. Furthermore, they are non-volatile and therefore suitable for digital cameras, mobile phones and other miniaturized computers.
A central processing unit. The main cache, a type of computer memory, is built into the CPU.
Two flash memory chips.
Adding RAM, or random access memory, to your computer can increase its performance.
MP3 players may have internal memory or rely on memory cards.
