In many other types of financial service “swap” and “trade” can be taken as synonyms, but in crypto they have quite different meanings.
Although the end result is essentially the same (start with one coin, end with another), their respective processes do vary.
Trading requires exchanging one cryptocurrency for fiat and then purchasing another coin with the fiat you obtained.
Swapping, on the other hand, allows users to seamlessly transfer one cryptocurrency for an equal amount in value of another. Transactions happen instantaneously, and without the need to first exchange crypto for fiat. Crypto exchanges offer up various “trading pairs”, asset combinations that can be swapped within their platform. Different swap services offer different trading pairs, and those allowing swaps between two very small or obscure coins may be more difficult to find.