RAM - Random Access Memory
Full Form of RAM is Random Access Memory, it is a type of
computer memory that can be accessed randomly, that is, any byte of memory can
be accessed without touching the preceding bytes. RAM is found in servers, PCs,
tablets, smart phones and other devices, such as printers.
Types of RAM
There are two main types of RAM:
1. SRAM (Static Random Access Memory)
2. DRAM (Dynamic Random Access Memory)
SRAM (Static Random Access Memory) – While DRAM is typically used for main memory,
today SRAM is more often used for system cache. SRAM is said to be static
because it doesn't need to be refreshed, unlike dynamic RAM, which needs to be
refreshed thousands of times per second. As a result, SRAM is faster than DRAM.
However, both types of RAM are volatile, meaning that they lose their contents when the power is
turned off.
DRAM (Dynamic Random AccessMemory) – The term dynamic indicates
that the memory must be constantly refreshed or it will lose its contents.
DRAM is typically used for the main memory in computing devices. If a PC
or Smartphone is advertised as having 4-GB RAM or 16-GB RAM, those numbers
refer to the DRAM, or main memory, in the device.
More specifically, most of the DRAM
used in modern systems is synchronous DRAM, or SDRAM. Manufacturers also
sometimes use the acronym DDR (or DDR2, DDR3, DDR4, etc.) to describe the type
of SDRAM used by a PC or server. DDR stands for double data rate, and it refers
to how much data the memory can transfer in one clock cycle.
In general, the more RAM a device
has, the faster it will perform.
The Difference Between Memory, RAM and Storage
Sometimes, people get confused about
the difference between memory and storage, in part because both can be measured
in megabytes (MB), gigabytes (GB) and
terabytes (TB).
In common usage, the term RAM is
synonymous with main memory. This is where a computing system stores data that it is
actively using. Storage systems, such as hard drives, network storage devices or cloud
storage, are where a system saves data that it will need to access later.
By contrast, storage is slower, but
it can retain data when the device is powered down. So, for example, if a
document has been saved to a hard drive prior to a power outage or system
crash, the user will still be able to retrieve it when the system is back up
and running.
Storage is usually less expensive
than RAM on a per-gigabyte basis. As a result, most PCs and smart phones have
many times more gigabytes of storage than gigabytes of RAM.
