The stars, whether they are giant or dwarfs, have born all of them in the same way and are formed from a same type of place.
This place are the nebulas, the place where the stars are born and where they start to grow. The nebulas are big concentrations of gas, mainly hydrogen and helium. These big concentrations of gas are grouping together into big lumps, which, in the future, will be the stars.
This lumps, attract every time more matter due to the increasing gravity, caused at the same time to the big association of matter. Being bigger, the gravity will do the rest, pressuring the star and causing the contraction of the star. Then, when the star will be contracted, and due to the high temperatures in the nucleus, this celestial body will start to fusion the hydrogen that he has, which will at the same time increase even more the temperature and then that the star fusion more elements.
After many time, the star will start to shine and the remainders of dust or gases will also group to form planets around the star, due to the gravity that there is. For this reason we can say that from the nebulas are formed the planets too. Like this formed the Earth, Mars, Venus… which in the end finished by obiting the Sun, our star.
Most of the stars that we observe in our universe form part of binary systems. The binary systems are systems formed by two stars which orbit one around the other. There are also many others formed by three or more stars. For example, we know one which consists of about 500 stars orbiting between them.
But how are these binary systems or even bigger formed?
The answer is very simple. Inside the nebulas, there is a so big quantity of gases, that is very probable that not an only star might be form, but that many other stars will form and of different sizes.