1. Computer composition

2. Data storage

  1. Computers internally use binary zeros and ones to represent data.

  2. All data, including files, images, etc., is eventually stored on the hard disk as binary data (zeros and ones).

  3. All programs, including operating systems, are essentially data of various kinds, also stored on hard disk in the form of binary data. When we install software, we actually copy the program files to the hard disk.

  4. The hard disk and memory are binary data.

3. Data storage unit

Size relation: bit < byte < KB < GB < TB<.....Copy the code
  • Bit: 1bit can hold a 0 or 1 (the smallest unit of storage)
  • Byte: 1B = 8B
  • Kilobytes (KB) : 1KB = 1024B
  • Megabytes (MB) : 1MB = 1024KB
  • Gigabytes (GB): 1GB = 1024MB
  • Terabyte (TB): 1TB is 1024GB

4. Program running

The process by which a computer runs software:

  1. To open a program, load the program’s code from the hard disk into memory

  2. The CPU executes the code in memory

Note: An important reason to use memory is because CPUS run so fast that reading data only from disk wastes CPU performance, so use faster access memory to store runtime data. (Memory is electricity, hard disk is mechanical)