A block is the smallest unit of data transfer in a storage device (HDD, SSD, etc.).
- The typical block size on a disk is 512 bytes or 4 KB, although it may vary depending on the device.
- When a read or write operation is performed, it is not done on a single byte but on a complete block.
- The operating system organizes files into multiple blocks to optimize access and data management.
Example
- If a program reads 1 byte from a file, the disk device actually reads the entire block (e.g., 4 KB).
- This allows the use of buffers in RAM and improves I/O speed.
See also
- [Page (virtual memory)]
- [Buffer]
- [I/O management]
