The article describes what they mean in a is considerably more understandable way.
>The history of the Milky Way is inscribed in the elemental composition of stars, because stars inherit the composition of the gas from which they are formed—in effect, stars "memorize" the element abundance in gas at the time they are formed.
Fun aside: Given the relation between temperature and density (i.e. hot gas is less dense than cold gas and compressing gases heats them up), it takes a large disturbance to coax interstellar gases to get dense enough to cause the cascading accumulation that becomes a star.
Metals play a critical role in this process [1]. By radiating away heat, they form the cool nuggets around which stellar material can accumulate. More metal in a gas cloud means faster star formation. That, by reducing the accumulation period before fusion blows away un-captured mass, produces smaller stars.
But what about before there were metals? The first generation of stars. Our models imply, without any metals to catalyse formation, the stars would have collapsed extraordinarily slowly. Fusion would have started very late, which means lots of material would have had a chance to fall into the neighborhood. The result? Truly massive short-lived stars, unlike anything our metallic universe could produce.
The article describes what they mean in a is considerably more understandable way.
>The history of the Milky Way is inscribed in the elemental composition of stars, because stars inherit the composition of the gas from which they are formed—in effect, stars "memorize" the element abundance in gas at the time they are formed.