Koinly definition of terms

As a new user, it is not clear to me the difference between an exchange and a swap. When I look at transactions in the tax report, I see some categorized as an Exchange and others as a Swap. When it is an Exchange, there is a profit connected to it. When it is a Swap, there is no profit listed. So, what is the difference between a Swap and an Exchange?

In like manner, I don’t understand the difference between a Trade and a Transaction. I have the option of deleting existing Trades or deleting existing Transactions but don’t know the consequences of either.

A list of definitions of terms used in Koinly would be a great help for new folks like me.