Memory Units
Computers · मेमोरी इकाइयां
📋Quick Overview
Computer memory stores data and instructions. Memory is measured in bits and bytes. 1 byte = 8 bits. Memory hierarchy goes from registers (fastest, smallest) to secondary storage (slowest, largest). RAM (Random Access Memory) is volatile (data lost when power off), while ROM (Read Only Memory) is non-volatile.
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1 Byte = 8 Bits; 1 KB = 1024 Bytes; 1 MB = 1024 KB; 1 GB = 1024 MB; 1 TB = 1024 GB
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RAM is volatile (temporary); ROM is non-volatile (permanent)
📖Memory Units
| Unit | Size | Equivalent |
|---|---|---|
| Bit | Smallest unit | 0 or 1 (Binary Digit) |
| Nibble | 4 bits | Half a byte |
| Byte | 8 bits | 1 character (e.g., A, 5, @) |
| Kilobyte (KB) | 1024 Bytes | ≈ 1 page of text |
| Megabyte (MB) | 1024 KB | ≈ 1 photo or 1 min MP3 |
| Gigabyte (GB) | 1024 MB | ≈ 1 movie or 250 songs |
| Terabyte (TB) | 1024 GB | ≈ 500 hours of movies |
| Petabyte (PB) | 1024 TB | ≈ Entire Netflix library x3 |
📖Types of Memory
| Type | Nature | Speed | Example |
|---|---|---|---|
| RAM | Volatile (temporary) | Fast | DRAM, SRAM, DDR4, DDR5 |
| ROM | Non-volatile (permanent) | Slower than RAM | PROM, EPROM, EEPROM |
| Cache | Very fast, small | Fastest after registers | L1, L2, L3 cache |
| Secondary | Non-volatile, large | Slowest | HDD, SSD, USB, CD/DVD |
| Flash Memory | Non-volatile | Fast | Pen drive, SD card, SSD |