[mndgs]

SEPA also works for SEK now, other EU currencies are in pipeline.

Swift is just a messaging standard and a message exchange network (distributed). SEPA is that, plus a settlement system (in a nutshell). That allows for speed and much more (instant payments, request to pay, pay by phone number, credit/debit transfers, etc).

You're bound to deal with currencies once you make any kind of transaction that originates in one currency and settles (finishes) in another.