The Om
One would know this sign from the Om chant that you hear at the beginning or the end of certain yoga classes. With a little hat on top, it looks a bit like the number 30. It is made up of the sounds of the letters A-U-M, Om is for threes.
The Om sign, with its origins in Hinduism, is said to signify the oneness of all life, including the heavens, the earth, and the underworld. Others claim this is a reflection of the three Hindu gods, Brahma, Vishnu, and Shiva.
Some claim the symbol's actual form reflects the word's syllables: the 'three' is the 'aahh' Sanskrit letter, the small 's' is the 'oooh' and the 'mmm' sound is the half-moon at the end. Om is considered one of the most powerful mantras, and for thousands of years, the practice of chanting Om has been performed.
There is a very special meaning to each part of the Om symbol: The dot at the top reflects the Absolute State or the 4th state of consciousness.
Read more at https://list.ly/list/5VnZ-yoga-symbols-explained