Dynamic RAM, commonly known as DRAM, is a type of random-access memory used in computers and other electronic devices. It is the most common form of RAM found in modern systems due to its cost-effectiveness and high-density capabilities. DRAM is used to store data and program code that the CPU (Central Processing Unit) needs to access quickly during active tasks.
The key characteristic of dynamic RAM is its dynamic nature. Unlike static RAM (SRAM), which uses bistable latching circuitry to store each bit of data as long as power is supplied, DRAM needs to be periodically refreshed to maintain data integrity. This is because DRAM stores data as electrical charges in tiny capacitors, and over time, these charges leak away, causing data loss. To prevent this, the memory controller of the computer or device sends refresh signals to the DRAM, rewriting the charge on each memory cell to maintain the stored data.
Though DRAM is slower and requires more power per bit than SRAM, it is much more space-efficient and therefore can offer significantly higher memory capacities at lower costs. This makes it ideal for applications where large amounts of relatively low-cost memory are needed, such as in personal computers, laptops, smartphones, and many other electronic devices.
DRAM comes in different generations, with improvements in speed, power consumption, and capacity. Some of the popular DRAM generations include SDRAM (Synchronous DRAM), DDR (Double Data Rate) SDRAM, DDR2, DDR3, DDR4, and DDR5 (as of my last update in September 2021). Each new generation brings higher performance and increased memory density, catering to the demands of ever-advancing technology and applications.