What energy conversion drives the initial temperature rise during a star's gravitational birth collapse?

Gravitational potential energy converted into thermal energy

The genesis of a star begins when a dense region within a vast cloud of gas and dust collapses under its own immense gravity. As this material falls inward toward the center, the stored gravitational potential energy possessed by the matter at greater distances is continuously transformed. This transformation process results in a substantial increase in the internal energy of the collapsing material, manifesting as a dramatic rise in temperature at the core. This heating process precedes the nuclear fusion stage; it creates the necessary high-temperature environment required for thermonuclear reactions to eventually ignite and sustain the star's luminosity.