The term "RAM," which stands for Random Access Memory, refers to any information storage medium which can store data. Although it's practically correct to refer to other storage devices like hard disks as RAM, different names were attributed to these in order to avoid confusions, and RAM remained the name for the PC memory.
How RAM Works
The working principle of RAM is quite simple: it uses electric power to read and write data. Although it delivers incredible speeds, its main drawback is that it constantly needs power in order to keep the data stored.
How Flash Memory Works
Flash memory works pretty much like RAM, but instead of constantly using electric power to retain the data, it stores it to capacitors. The advantage of being able to keep the data even when not powered is great but a disadvantage is the speed as it takes longer to store data to flash memory.
The RAM is the fastest memory available, providing very high read/write speeds and lowest access times. Compared to the access speeds of other storage mediums like hard disks (HDD) or flash memory, which are measured in milliseconds, the access times of RAM is measured in nanoseconds, making it thousands of times faster than any other storage solution.
For its high speeds, RAM was chosen for computers, where fast communications between the memory and the CPU was required. The RAM is used to load up the essential files needed by a computer to operate properly, thus giving you instant access to the files.
Flash memory is used as an alternative to the other storage mediums, like hard disk drives, CDs, or DVDs. Flash memory is chosen because it involves no moving parts, it's all electronic, thus making it more reliable. Also, its size presents another great advantage, as flash memory cards are very small, yet deliver high storage spaces, which makes them perfect for portable devices such as music players, digital cameras or PDAs.
Importance of RAM
Many devices use RAM in parallel with flash memory to achieve a better performance. While the flash memory is basically used for the actual storage of the files, these are copied into the RAM while the device is on to allow quicker access to them, improving the response time and the overall performance of the device.