What gives Superman his power?

As a subject matter expert in comic book lore, particularly with regard to the DC Universe, I can provide a detailed explanation of what gives Superman his powers. Superman's abilities are derived from his alien biology and the Earth's yellow sun.

Superman, also known as Kal-El, is a native of the planet Krypton. His biological makeup is inherently different from that of humans, which grants him certain inherent abilities on his home planet. However, it is the exposure to Earth's yellow sun that significantly amplifies these abilities, making him the "Man of Steel" we know.

The yellow sun emits a type of radiation called solar energy, which Superman's cells can absorb and convert into energy. This process is what gives him his incredible strength, speed, invulnerability, and other powers. Without the sun's radiation, Superman would be much weaker, as seen in storylines where he is in environments without a yellow sun, such as in space or near a red sun, which has the opposite effect and drains his powers.

In addition to solar energy, Superman also has a few other vulnerabilities and sources of power.
Kryptonite, a mineral from his destroyed home planet, can weaken or harm him, depending on its color and composition.
Red sunlight can temporarily remove his powers, as it does not provide the necessary radiation to fuel his abilities. And Vulnerability to magic is another aspect that can challenge him, as magic can sometimes bypass his physical invulnerability.

Superman, a Kryptonian, flies toward the Earth's yellow sun to recharge his powers. The Photonucleic Effect is the effect by which Kryptonians and creatures from the planet Krypton and, presumably, Daxam as well, are given incredible superpowers by exposure to Earth's Yellow sun.