Unit 1 · Data representation
1.3 Data storage and compression
By the end of this section you should be able to
- 1.3.1 Name the units of data storage from bit to exbibyte
- 1.3.2 Calculate the file size of an image and a sound file, using 1024
- 1.3.3 Explain the purpose of and need for data compression
- 1.3.4 Explain lossy and lossless compression, including run length encoding
Lessons
Key vocabulary
- Nibble
- A group of 4 bits.
- Byte
- A group of 8 bits.
- Kibibyte (KiB)
- 1024 bytes.
- Mebibyte (MiB)
- 1024 kibibytes.
- Compression
- Reducing the size of a file, so it needs less storage and bandwidth and transfers faster.
- Lossy compression
- Reduces file size by permanently removing some data.
- Lossless compression
- Reduces file size without permanently losing any data.
- Run length encoding (RLE)
- A lossless method that stores a run of repeated values as the value and a count.