Topic 1: Binary Basics (Bits, Bytes & Representation)

What is a bit?

A bit (binary digit) is the smallest unit of data in computing. It can only be 0 or 1.

What is a byte?

A byte = 8 bits. It’s the basic unit used to represent characters, numbers, or data in computers.

How many bits are in 2 bytes?

There are 16 bits in 2 bytes, as each byte contains 8 bit

Why do computers use binary instead of decimal?

Computer circuits only recognize two stable states — on (1) and off (0). Binary matches this design, making processing faster and more reliable.

What does “binary” mean?

Binary means “base 2” — numbers are made from only two digits (0 and 1).

What’s the relationship between bits and data interpretation?

The same bit pattern can represent different things (e.g., a number, a letter, or a colour) depending on context or data type.

How many bytes are in 1 kilobyte (KB)?

1 KB = 1024 bytes = 8192 bits.

Give an example of the same bit pattern meaning different things.
01111000 could mean:

• Decimal 120 (unsigned)

• Character 'x' (ASCII)

• A value in an image pixel, depending on context.

What determines a bit pattern’s meaning?

The context or data type (e.g., unsigned integer, two’s complement, ASCII). The number of bits and the first bit (sign bit) can also affect meaning.

Why do humans use decimal instead of binary?

Because we have ten fingers — base 10 evolved naturally for human counting.