The nishan sahib is a type of flag or banner that is very important in the Sikh religion. It's kind of like what you see outside of a store or building to show that it belongs to a certain group of people.
The nishan sahib is usually made out of a pretty, bright yellow fabric, and it has a very special symbol on it called the Khanda. The Khanda is made up of a double-edged sword, two curved swords, and a circle in the middle.
Sikhs really like the nishan sahib because it's a sign that they are part of the group and that they have something in common with other Sikhs. It also serves as a reminder to be brave and to stand up for what is right, which are very important values in the Sikh religion.
The nishan sahib is usually put on top of a special tall pole called a flagpole. The flagpole and the nishan sahib are usually located outside of a Sikh temple, which is called a Gurdwara. When someone sees the nishan sahib outside of a Gurdwara, they know that it is a special place where they can go to pray, learn, and be with other Sikhs.