Bits and encoding.
WHAT EVERYTHING REDUCES TO
Two states, represented as one and zero.
WHY TWO
Electrical circuits distinguish two states reliably. More states would not be reliable.
WHAT A BIT IS
One such value.
WHAT A BYTE IS
Eight bits, which can represent a range of values sufficient for a character in basic text.
WHAT THAT MEANS PRACTICALLY
All data is numbers, interpreted according to a convention.
WHAT DETERMINES THE INTERPRETATION
The format, indicated by the file type and its internal structure.
WHY A FILE OPENS WRONGLY
Because it was interpreted using the wrong convention.
WHAT TEXT ENCODING IS
The convention mapping numbers to characters.
WHY IT CAUSES PROBLEMS
Different conventions exist, and using the wrong one produces unreadable characters.
WHAT TO PREFER
The current international standard, which covers virtually every writing system.
WHAT ELSE IS ENCODED THIS WAY
Images, audio, video and every other kind of data.
WHAT THAT EXPLAINS
Why a file can be copied perfectly, and why corruption is visible as nonsense.
