【Existence】 , 【being】 ,  【actuality】  are closely related in meaning but not always interchangeable.

【Existence】 is the inclusive term which designates the state or condition of anything regarded as occurring in space or time, as distinct and apart from all other things, and as having a nature or substance of its own.

The opposite of  【existence】  is its complete negation nonexistence.

【Being】 , when it denotes 【existence】 , adds varying implications. Sometimes it implies life, consciousness, or personality. Sometimes it implies fullness or completeness of 【existence】 and absence of imperfection.

Sometimes it suggests the complex of qualities or characteristics that constitute the nature of a person or a personified thing.

【Actuality】  as a synonym of  【existence】  stresses realization or attainment; it usually implies opposition to possibility or potentiality.