WHAT IS BRAHMAN?

IN ADVAIDA BRAHMAN OR SELF IS SAID TO BE THE ONLY REALITY. AND WHATEVER IS OTHER THAN THAN SELF IS MAYA OR ANITHYAM.PURE KNOWLEDGE OR CONSCIOUSNESS CONSTITUTES THE ESSENCE OF SELF AND THIS CONSCIOUSNESS IS REAL. IT'S BEYOND ALL CHANGES,MODIFICATIONS,HENCE REAL. THE SELF IS NIRVISHESHA[CANNOT BE CHARACTERISED]NIRGUNA[DEVOID OF ANY QUALITY]NISHKRIYA[INACTIVE]NIRVIKARA[WITHOUT MODIFICATION]SHUDDHA[WITHOUT ANY IMPURITIES]SATCHITANANDASWARUPA[EXISTENCE-CONSCIOUSNESS,ETERNAL HAPPINESS . PURE AWARENESS  IT IS NEVER NEGATED.CONSCIOUSNESS ALONE EXISTS.THERE IS ONE AND ONLY ONE CONSCIOUSNESS HENCE ADVEETHIYAM. ACCORDING TO ADI SHANKARA THERE IS BRAHMAN AND BRAHMAN ALONE.[AKHANDAM SATCHIDHANDAM AVANGH MANAS GOCHARAM, ATMANAM AKHILADHARAM, ASHRAYE ABHEESHTTA SIDDHAYE.]ATMA CANNOT BE DIVIDED,IT'S SAT-CHIT ANANDA, WORDS CANNOT DESCRIBE SINCE NOT AN OBJECT,MIND CANNOT REACH THERE,WHOLE UNIVERSE IS BASED ON ATMA,ONE WHO TAKES SHELTER IN BRAHMAN IS ALREADY  A SIDDHA.