This one is prone to confusion because of their usage among Spanish speaking countries. Many people use "anuncio", "aviso", "publicidad" and "propaganda" as synonyms for "advertisement", but each of them can have different meanings or usage depending on the context.

▪️News, updates, modifications, change of plans/schedule

🇪🇸 Hacer un anuncio
🇬🇧 To make an announcement

🇪🇸 Dar aviso de algo, recibir un aviso
🇬🇧 To notify something, to receive a notification

(Note: in Spanish there are also the words "notificar" and "notificación")

▪️Classified adverts, small ads

🇪🇸 poner un anuncio / un aviso en el diario
🇬🇧 to put an ad in the newspaper

▪️Commercial advertising, informative campaign, coverage of an event

🇪🇸 Y ahora pasemos a la publicidad
🇬🇧 And now for the adverts
🇺🇸 And now for a commercial break

🇪🇸 La publicidad de Coca-Cola
🇬🇧 The advert of Coke

🇪🇸 Le han dado mucha publicidad a la boda real
🇬🇧 The royal wedding has been given a lot of publicity

▪️Usually political campaign, infomation about political organisations, but also (in spoken language) commercial advertising

🇪🇸 la propaganda política / electoral
🇬🇧 political / electoral advertising

🇪🇸 reparte propaganda por las casas
🇬🇧 he delivers advertising material door to door

🇪🇸 les han hecho mucha propaganda por televisión
🇬🇧 they've been advertised a lot on television

#tip