Stars are different. The giant star has a relatively low surface temperature, about 5000 degrees and a huge radius, reaching 800 solar, and due to such large dimensions, an enormous luminosity.
Red giants are stars with low temperatures (3000 – 5000 K), but with an enormous luminosity, 100 times the luminosity of the Sun. The absolute stellar magnitude of such objects is from -3m to 0m, and their maximum radiation is in the infrared range. Almost all red giants are variable stars. Inside the red giants, further thermonuclear transformation of helium takes place (helium – into carbon, carbon – into oxygen, oxygen – into silicon, and finally – silicon into iron).
The blue giant is an O or B spectral class. These are young, hot, massive stars. The masses of blue giants reach 10-20 solar masses, and the luminosity is thousands of times higher than that of the Sun.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.