Computing Revision

Computing Revision

1. Sound

   • How does a sound card convert analogue to digital? It uses voltage (e.g. through a microphone) and then sampled at intervals which is known as the sounds sample rate

2. Compression Types

   • Lossy
     • What is lossy compression? Compression where quality is lost but file size is greatly reduced
   • Lossless
     • What is lossless compression? Compression where file size is reduced but quality remains the same.

3. File Measurements

   • Bit, Byte, Kilobyte, Megabyte, Gigabyte, Terrabyte
   • 8 bits = 1 byte, 1024 = 1 kilobyte, 1024 kilobyte = megabyte, 1024 megabyte = 1 gigabyte, 1024 gigabyte = 1 terrabyte

4. Arrays

   • A variable is a memory location that can store a value. It can be thought of as a box in which values are stored. The value held in the box can change, or vary. But each variable can only hold one item of data.