What is "aikyam"

'''Aikyam ' ( Sanskrit: ऐक्यम्) means – oneness, unity, harmony, unanimity, identity or sameness or identical. All thoughts of the Upanishads move around two fundamental ideas – Brahman and the Atman; as a rule these terms are used synonymously, there is no difference between these two. The main theme of Vedantic teaching is identity of the individual and the Total (jiva isvara aikyam), that the self (Atman) and awareness ( Chaitanya ) are identical (aikyam''). Aikyam means oneness or identity.