Thai Buddhist Flag: "Thong Dhammacak"

This is a Thai Buddhist flag.

Theravada Buddhists in Thailand developed their own Buddhist flag, colored yellow with a red "dharmacakka", or the wheel of dharma. This flag is sometimes paired with the international Buddhist flag. It was officially adopted in 1958 by Buddhist monks, and flown outside temples alongside the national flag and on important events.

Buddhism is a religion in which people follow the teachings of the Buddha (Siddhartha Gautama) who lived and taught about 2500 years ago. Buddhists do not believe in a personal creator god. Buddhists believe in the Four Noble Truths, including that life is suffering because we are attached to our desires, but that suffering and attachment can be ended by living according to the Noble Eight-fold Path (ex. right thinking, right working, right speaking). The holy book is called the Tripitaka. It contains the teachings of the Buddha. Buddhists believe in rebirth after death (reincarnation). Their goal is to become Enlightened, to achieve Nirvana, and break the cycle of birth and death.
Source:
https://en.wikipedia.org/wiki/Buddhist_flag