Polysyndeton refers to the process of using conjunctions or connecting words frequently in a sentence, placed very close to one another. Opposed to the usual norm of using them sparsely, only where they are technically needed. The use of polysyndetons is primarily for adding dramatic effect as they have a strong rhetorical presence.
a) Saying “here and there and everywhere”, instead of simply saying “here, there and everywhere”.
b) “Marge and Susan and Anne and Daisy and Barry all planned to go for a picnic”, instead of “Marge, Susan, Anne, Daisy and Barry…” emphasizes each of the individuals and calls attention to every person one by one instead of assembling them as a group.