Insulator
convection
A toaster uses radiation.
Yes it is the main method of making toast.
A classic toaster (bread toaster) is mostly radiation with a little convection. The heating elements radiate their heat onto the contents of the toaster. (In a "toaster over" there is much more convection when the oven is closed, and it functions like a conventional oven, cooking mainly with the trapped heated air.)
toaster
A good example of conduction is the way your electric stove heats the pot. On contact, the heat from the burner transfers to the pot through conduction.
It is an example of conduction
toaster oven
solid
Transfer
Transfer
Yes.