Byte

1. Maximum a row of 8 bits

2. Bits

2.1. binary: 0 or 1

2.2. Long rows are tedious

3. Hexadecimal notation

3.1. Use of symbols

3.2. Combination of bits

4. Prefixes for multiples of bits

4.1. kilo-

4.2. mega-

4.3. giga-

4.4. Tera-

5. Key unit

5.1. In computing worlds

5.2. In telecommunication worlds