Difference between internal sorting and external sorting

Difference between internal sorting and external sorting is a DSA topic. In plain words you use it for names A→Z in the roll list. Don’t start with a slogan — start with that picture.

Smallest example: n log n vs n². Type it, run it, and say what you see. If you can do that from memory, you know Difference between internal sorting and external sorting.

From the example next to this theory — Difference between internal sorting and external sorting: dry-run [4, 1, 3].

Trap — unstable sort when equal keys matter. Fix that before you talk about advanced DSA.

Viva — what is Difference between internal sorting and external sorting? Then show n log n vs n². Then name the trap.