What is the difference between link farming and link exchanging?

[SadaAlnsyan]

Link farms are the junkyard of SEO - a mass‑produced black‑hat circus of dead‑weight PBNs spitting out fake link juice that'll get you a de‑index faster than you can say "penalty."
Link exchanging, when framed as a legit content barter, is still a gray‑area hustle, but at least it isn't a full‑blown spam farm.

[VivaFenester]

Both are about backlinks—but one is basically spam at scale, while the other can be legitimate if done carefully.

[Netrunner]

Link farming = blackhat SEO

Link exchanging = grey hat SEO

Google knows when site A exchange a link with site B. The best way now is to do it with a third site.