I'm copy/ pasting this from the internet. But basically Los Hongos are describing any fungus whether it's mold on bread, that which grows in unsanitary places, and maybe also mushrooms in a scientific sense. Las Setas describe specifically wild mushrooms. And Los Champiñones are the type of mushrooms used in common cooking.
"When I was in Spain eating champiñones I asked my host dad if there was a difference between hongos and champiñones and he said that champiñones are a type of hongo. My host mom also made a dish with setas which I saw somewhere as translated as "wild mushrooms." "
In Canary Island and in other places of Spain, champiñones means a kind of agaricus, not all mushrooms. Hongo if it said like general mushroom. However, also it said for a kind of boletus.
If someone want to practice Spanish and English it would be fantastic. I have a middle/low level of English.
In Costa Rica the restaurants and grocery stores use "hongo" for mushroom--salsa de tomate con hongos, for example. Pharmacies also use "hongo" for athlete's foot or toenail fungus, which caused my mother no end of confusion. Meanwhile I've never seen "champiñones," but maybe I've been looking in the wrong places.
(SP) - (PT) - (EN)
SETA (sometimes champiñón) - cogumelo - mushroom - in french "champignon"
- maybe spanish speakers use "hongo" in general for any kind of fungus, including mushrooms, but I'm not completely sure
hongo - fungo - fungus
champiñón (champiñón común) - champignon (also champignon de Paris/cogumelo Paris) - portobello mushroom
flecha - SETA (or "flecha") - arrow
señales de giro (turning signs) - SETAS de direção (literally turnin arrows)- turning sign (those yellow/orange blinking lights when driving)