What is the name given to a baby star that shines due to gravitational heating but not yet through fusion?

Answer

Protostar

The heat generated during the gravitational compression phase turns the collapsing mass into a protostar, which radiates energy but has not yet achieved the core conditions necessary for sustained nuclear fusion.

What is the name given to a baby star that shines due to gravitational heating but not yet through fusion?
heatenergynuclear fusionstarastrophysics