Okay, imagine there was a really wise and powerful person named Bhishma. He was a bit like a grandpa who everyone looked up to and listened to. He was also really good at fighting and protecting people.
But, there was a problem. Bhishma made a promise a long time ago that he would never get married or have any children. This was because of a promise he made to his father.
Because of this promise, Bhishma never had a family of his own, and he became known as someone who always put his duty above everything else. He would do anything to protect his family and kingdom, even if it meant sacrificing his personal happiness.
Eventually, Bhishma became an important person in a really big story in India called the Mahabharata. He fought in a huge battle to protect his kingdom, and even though he was really old, he was still an excellent warrior.
So, in simple terms, Bhishma was a wise and powerful person who always did his duty and never put his personal desires before what was right. He was known for his strength and loyalty and played a big role in a famous story.