Program

A set of syntactical characters that describe some kind of behavior (semantics), defined by a Programming Language.

Programs can take many forms.

Program Form	What it is
ADD R6, R6, -1	Assembly instruction to decrement
x = 5	Assignment instruction of x as 5
$f(x,y)=g(x,5),g(x,y)=x^2+y^2$	Definition and partial application of a function
fib(x) { fib(x - 1) + fib(x - 2) }	Definition of a recursive function
$E(2)⟺2=2k,s.t.k\in \mathbb{Z},1\in \mathbb{Z}\therefore E(2),\square$	Proof that 2 is even
$H=\frac{1}{1-\mathcal{R}}=\frac{Y}{X}$	Operator transfer function of an accumulator representative of block diagram / digital circuit

C Program Pipeline

Note that an Assembler isn’t shown, because a separate step for assembling is slower. You would only do that if you were very limited in Memory, e.g. you are in 1970.