Maturita 2026

Vzhled

Stáhnout jako MD

Storage Devices ​

1. What storage means ​

  • Storage = where data is kept, both short-term and long-term.
  • Different from RAM, which is volatile memory used only while the computer is on.
  • Long-term storage is non-volatile – it keeps data even when the power is off.

2. Levels of memory (hierarchy) ​

  • Registers – inside the CPU, fastest, tiny.
  • Cache (L1, L2, L3) – very fast, small, on or near the CPU.
  • RAM (Random Access Memory) – fast, volatile, gigabytes.
  • Secondary storage – SSD, HDD; non-volatile, large.
  • External / removable – USB sticks, SD cards, external drives.
  • Cloud storage – over the internet.
  • Backup / archive – tapes, optical discs, cold storage.

3. HDD – Hard Disk Drive ​

  • Mechanical device with spinning magnetic platters and a read/write head.
  • Pros: cheap per gigabyte, very high capacity (up to ~22 TB).
  • Cons: slow compared to SSD, noisy, sensitive to shocks, higher power use.
  • Common in desktops, servers, NAS, external backups.

4. SSD – Solid State Drive ​

  • Uses flash memory (NAND), no moving parts.
  • Pros: very fast (especially NVMe), silent, low power, shock-resistant, lightweight.
  • Cons: more expensive per GB; cells have limited write cycles.
  • Interfaces: SATA (older, slower), NVMe via M.2 / PCIe (much faster).
  • Modern laptops and gaming PCs almost always use SSDs.

5. USB flash drives ​

  • Small, portable, easy to use, plug-and-play.
  • Capacities from a few GB to several TB.
  • Convenient for moving files between computers.
  • Easy to lose or damage.

6. Memory cards ​

  • SD cards – standard size, used in cameras, laptops.
  • microSD – smartphones, drones, dashcams, Raspberry Pi.
  • CompactFlash – pro cameras.
  • Different speed classes (Class 10, UHS, V30 / V60 for video).

7. Optical media ​

  • CD (~700 MB), DVD (~4.7 / 8.5 GB), Blu-ray (~25 / 50 / 100 GB).
  • Mostly obsolete for everyday use, still used for movies, archives, music.
  • Burnable types: CD-R/RW, DVD-R/RW, BD-R/RE.

8. Magnetic tape ​

  • Old technology but still in use for enterprise backups (LTO).
  • Very cheap per TB, slow access (sequential only).
  • Long-term archiving in banks, libraries, big companies.

9. Cloud storage ​

  • Files stored on remote servers, accessed via the internet.
  • Providers: Google Drive, OneDrive, iCloud, Dropbox, Mega, pCloud.
  • Pros: access from anywhere, sync across devices, easy sharing, backup, scalable.
  • Cons: needs internet, privacy and security concerns, subscription fees, vendor lock-in.

10. NAS – Network Attached Storage ​

  • Storage device connected to the home or office network.
  • Brands: Synology, QNAP.
  • Used for: backups, media server, private cloud, file sharing.

11. Backups (3-2-1 rule) ​

  • 3 copies of important data.
  • On 2 different media.
  • With 1 copy off-site (cloud or another location).
  • Protects against failure, theft, ransomware, fire.

12. Units of data ​

  • Bit (b) → Byte (B) = 8 bits → KB → MB → GB → TB → PB.
  • 1 KB ≈ 1,000 B (decimal) or 1,024 B (binary, KiB).
  • Modern phones come with 128 GB – 1 TB; laptops 256 GB – 4 TB.

13. Useful vocabulary ​

  • Capacity, read / write speed, IOPS, latency, throughput.
  • To format, partition, mount, eject.
  • File system: NTFS (Windows), APFS / HFS+ (macOS), FAT32 / exFAT (compatibility), ext4 (Linux).
  • To back up, restore, sync, share, encrypt.

14. Speaking strategy ​

Distinguish RAM from long-term storage. Compare HDD vs SSD (and say why SSD wins for performance). Mention USB sticks and SD cards as portable storage. Cover cloud storage as the modern default for users. End with backups (3-2-1 rule) as good practice everyone should follow.