While many refer to a client, such as a ionomy QT, as a "wallet", it is not. A wallet is the collection of private keys that the client uses to interact with the ionomy network. While programs like the ionomy QT client are not "wallets" it is common to refer to them as "wallets".
The ionomy QT client is a program that runs on your computer that presents the user with an easy to use visual interface. The QT wallet is usually run on desktop machines or by users who prefer a graphical interface.
The iond daemon is a program that runs in the background.
A daemon is a computer program that runs as a background process, and usually does not have any GUI (Graphical User Interface). iond is usually run on server environments or by users with more experience.