How is heat transfered?& wat causes heat to be transferred.(conductors and insulators)?

Heat is the vibration and movement of atoms and molecules. In the process they bump into each other. If something is hot, it's molecules are moving faster with more energy (kinetic, motion energy). Heat is transferred when they hit other molecules that are not as hot (moving slower or with less energy) and causes them to speed up and the hotter ones to slow down, thereby transferring energy across. I don't know what level of answer you need but try http://en.wikipedia.org/wiki/Heat_transfer for a higher level more detailed answer.