Explain the concept of RAM and cache memory. Write the types of cache memory.

RAM (Random Access Memory) is the main temporary working memory of the computer. It holds the OS, open programs and data currently in use. It is volatile — contents are lost on power off — and much faster than hard disk but slower than cache.

• If RAM is 4 GB, only limited programs run smoothly; 8–16 GB allows multitasking with Word, Excel, browser and email together.
• Types: SRAM (fast, costly) and DRAM/SDRAM/DDR (common main memory).

Cache memory is ultra-fast SRAM placed between CPU and RAM to reduce waiting time. The CPU keeps copies of frequently used instructions there.

Types of cache:

1. L1 cache — Smallest (KBs), fastest, inside each CPU core; stores immediate instructions.
2. L2 cache — Larger (256 KB–2 MB), per core or shared; backup to L1.
3. L3 cache — Largest (MBs), shared among all cores; reduces trips to RAM.

Exam line: RAM = working table, Cache = pocket for most-used tools — bigger cache + sufficient RAM = faster computer.