How can fusion reactors provide unlimited power to humanity?

(N/A) The natural thermonuclear fusion process in a star is replicated in a thermonuclear fusion device. In controlled fusion reactors,the aim is to generate steady power by heating the nuclear fuel to a temperature in the range of $10^{8} \ K$.
At these temperatures,the fuel exists as a mixture of positive ions and electrons,known as plasma. The primary challenge is to confine this plasma,as no physical container can withstand such extreme temperatures.
Several countries around the world,including India,are developing advanced magnetic and inertial confinement techniques to address this. If successful,fusion reactors will provide a clean,safe,and almost unlimited source of energy to humanity.