Almost everything. The main thing is that the size dictates the rate of fuel consumption (larger stars using more fuel). So a larger star will burn hydrogen faster (and hence it will be brighter and more short-lived). Really big stars can fuse larger atoms than hydrogen, eventually forming iron. These stars end up as neutron stars or black holes. smaller stars like the Sun can only burn hydrogen and helium. These stars last a long time and don't explode when they run out of fuel. Really really small stars can burn for hundreds of billions of years (theoretically, we can't know for sure because the universe isn't old enough).
Ok well not everything but all the things astrophysicists really care about.
It is important to know about the mass of a star because the mass affects what happens in the later stages in its life cycle. Stars with the highest mass have the shortest life because they use up their supply of fuel rapidly. Stars with very low mass have the longest life, just like our sun, because it takes a very long time to use up their supply of fuel.
The more mass a star has, the more quickly it fuses its hydrogen supply and therefore the more quickly it 'dies.' When fusion in the core stops, the star undergoes an event depending on its mass. At this point at which fusion stops, compression from gravity exceeds outward expansive force of the star's energy. The most massive of stars (Blue giants and supergiants) explode in the most violent events in the observable universe, supernovae (singular supernova). Slightly less massive stars, depending on composition, may form either a smaller supernova, or a black hole. Yet smaller stars may form a neutron star, the densest forms of stars, which can have many times the mass of an average star while only the size of a large city. Stars like our sun (Sol) eject most of their matter into space, leaving behind a slowly cooling remnant called a white dwarf star. The ejected matter forms a nebula which will eventually form a new solar system. Stars that are slightly smaller than our star, which is classified as a yellow dwarf, red dwarves, tend to simply die out and form white dwarves without exploding, or with very minor deaths. The final classification of stars, brown dwarves, are so cool that they do not have a specific 'death' event, but simply slowly shrink and cool until they fade away (it is notable however that comparatively little is known about brown dwarves because they are so difficult to observe, being very dim).
Ultimately, the fate of a star can be described in one general trend: the more massive and the hotter the star is, the more violently it collapses, and the greater the remnant it leaves behind.
It's size, temperature and ultimate demise.
Basically, the more massive a star, the brighter it will shine, and the shorter will be its lifetime.
mass
mass
Surface Temperature, and mass.
It's Mass
Their mass. If its mass is nearly like of sun it will become red giant. If its much bigger, it will become super giant
Its mass.
Its Mass.
MASS
its mass
The star's mass determines the temperature in its core. A stars mass will also determined it size and the amount of gravitational pull it will have.
The mass of the star
mass
The mass of the star.
mass
The mass of the host star.
the star's mass, chemical composition, and size of it when it is born
The colour of the star is determined by its age , mass , and composition.