What is RAM? Distinguish between SRAM and DRAM.

Random Access Memory (RAM)

RAM (Random Access Memory) is a volatile semiconductor memory used in computer systems to store temporary data and instructions that are being processed by the central processing unit (CPU). RAM allows for quick access and retrieval of data, enabling efficient execution of programs and operating systems. The data stored in RAM is erased when the power is turned off.

There are two main types of RAM commonly used in computer systems: Static RAM (SRAM) and Dynamic RAM (DRAM).

Static RAM (SRAM)

• SRAM is a type of RAM that uses a flip-flop circuit to store each bit of data.
• It consists of six transistors arranged in a latch configuration, forming two cross-coupled inverters that hold the data in a stable state without the need for constant refreshing.
• SRAM is faster and has lower power consumption compared to DRAM.
• However, SRAM is more expensive and has a lower storage capacity per unit area compared to DRAM.
• SRAM is commonly used in cache memory, which is a high-speed memory used by the CPU to store frequently accessed data and instructions, improving the overall performance of the system.

Dynamic RAM (DRAM)

• DRAM is a type of RAM that uses a capacitor to store each bit of data.
• It consists of a single transistor and a capacitor arranged in a memory cell.
• DRAM requires periodic refreshing to retain the stored data, as the capacitor tends to lose its charge over time.
• DRAM is less expensive and has a higher storage capacity per unit area compared to SRAM.
• DRAM is commonly used in main memory, which is the primary memory used by the computer to store programs and data that are being processed.

SRAM and DRAM have different characteristics and are used for different purposes in computer systems. SRAM is faster and more power-efficient but more expensive and has a lower storage capacity. DRAM is less expensive and has a higher storage capacity but requires refreshing and has a longer access time compared to SRAM.

Comparison of SRAM and DRAM

Characteristic	SRAM	DRAM
Memory Cell	Flip-flop circuit	Capacitor and transistor
Speed	Faster	Slower
Power Consumption	Lower	Higher
Cost	More expensive	Less expensive
Storage Capacity	Lower	Higher
Refreshing	Not required	Required
Usage	Cache memory	Main memory