How binary encodes numbers, text and images, how storage capacity is measured, and the social and ethical questions that computing raises.
6 free units in this chapter
Raw data only becomes valuable when it is processed into information, and information becomes knowledge when people interpret and apply it to make decisions.
About 3 minComputers work in binary (base 2) because circuits have two reliable states: on and off. Programmers also use hexadecimal (base 16) as a compact way to write binary.
About 4 minEverything a computer stores — text, numbers, images — is ultimately encoded as binary. Programming languages give us primitive data types so the computer knows how to interpret those bits.
About 4 minGood file management means you (and your programs) can find, protect and back up data quickly. The operating system organises storage as a tree of drives, folders and files.
About 3 minA file extension tells the operating system (and you) what kind of data a file holds and which program should open it.
About 3 minStoring personal data digitally raises real responsibilities: who may see it, how long it is kept, and what happens if it leaks.
About 4 min