Algorithms, loops and abstraction
An algorithm is a clear set of steps in order; abstraction hides the detail you do not need right now.
A worked example
Drawing a square is "repeat 4 times: move forward 100, turn right 90". The loop replaces four copies of the same two instructions.
The mistake people actually make
When a program does the wrong thing, trace the steps in order to find the faulty one rather than rewriting the whole thing. Breaking a problem into parts does not remove it, it makes each part testable.