What is the main feature of main sequence stars?

The stars of the main sequence are in a stationary state, in which the force of pressure of an incandescent gas heated by thermonuclear reactions balances the force of gravity.

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.