BeginnerTopic 15 of 104Software & Computing
Binary and data representation
Everything is stored as bits; text uses encodings such as UTF-8.
In depth
Computers store everything as bits. Integers use binary or two's complement, reals use IEEE 754 floating point, text uses encodings, images use pixel arrays and sound uses samples. Understanding representation explains overflow, precision limits and file sizes.
Key points
- Endianness
- Hexadecimal notation
- Bits, bytes, KB vs KiB
ExampleA 24-bit RGB pixel needs 3 bytes; a 1920×1080 image is about 6 MB uncompressed.
Computers store everything as bits, so understanding representation explains overflow, precision and why text can be garbled.
What is Binary and data representation?
Everything is stored as bits; text uses encodings such as UTF-8.
Why is it important to understand binary and data representation?
Computers store everything as bits, so understanding representation explains overflow, precision and why text can be garbled.
What is UTF-8?
A variable-length encoding for Unicode text, which uses one to four bytes per character and is compatible with ASCII for common letters.
Why does the same bit pattern mean different things?
The meaning depends on the type and encoding used to read it, such as an unsigned integer, a signed integer or a character.
How is Binary and data representation used in practice?
Typical applications include explaining why a counter overflows after 255 in an 8-bit variable, converting a sensor value to hex for a device register and fixing garbled characters caused by the wrong encoding.
What should I learn before Binary and data representation?
Study "Command line basics" first (topic 14 of 104 in Software & Computing). It covers the groundwork this topic builds on.
What are the key points of Binary and data representation?
Endianness. Hexadecimal notation. Bits, bytes, KB vs KiB.
Can you give an example of Binary and data representation?
A 24-bit RGB pixel needs 3 bytes; a 1920×1080 image is about 6 MB uncompressed.
What comes after Binary and data representation?
The next topic is "Big-O notation", which builds directly on this one.
How difficult is Binary and data representation?
It is classed as Beginner in Software & Computing (topic 15 of 104). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.