Stars die when they run out of fuel for the fusion reaction that is going on at their centers. Some stars have more fuel (or mass) but these large stars also tend to burn their fuel faster.

Our Sun is a pretty average star. It is expected to start to die in about 5 billion years. Towards the end, when it starts to run out of fuel it will expand to become a red giant. After losing its outer layers it will shrink to become a white dwarf.

Unfortunately for the inner planets the red giant phase is expected to result in the outer edges of the Sun reaching Earth, so all the inner planets will be consumed. There is some uncertainty to how much the Sun will expand, so there is some possibility that it won't swallow up the Earth, but the Earth will certainly be very close to the Sun and too hot to support life.