<aside> 💡 key concept

A computer system is a collection of hardware and software components that work together to run computer programs.

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1.1 Information is Bits in Context

source program (or source file):

The source program is a sequence of bits, each with a value of 0 or 1, organized in 8-bit chunks called bytes. Each byte represents some text character in the program.

text representation

Most modern systems represent text characters using the ASCII standard that represents each character with a unique byte-sized integer value.

the ASCII text representation of hello.c

text file & binary file

Files such as hello.c that consist exclusively of ASCII characters are known as text files. All other files are known as binary files

a fundamental idea

All information in a system — including disk files, programs stored in memory, user data stored in memory, and data transferred across a network is represented as a bunch of bits. The only thing that distinguishes different data objects is the context in which we view them

1.2 Programs are Translated by Other Programs into Different Forms

high level C language —>compiler driver —>low level machine language

source file—> compiler driver —>executable object file

(and the transation instructions are packaged in a form called an executable object program