Being is a term which denotes 'existence', it is just something rather than nothing. It is opposed to 'non-being'. In the entire history of western thought and philosophy, 'Being' has been subject to various interpretations. However, with thinkers like Heidegger, what remained of 'Being' at each stage having moved further and further away from the main process of philosophizing, was contracted to Dasein. [1]
Being and non-being are the two aspects of the fundamental stage of the dialectical process of development. Hegel speculates in his Phenomenology of Spirit that for nothing to exist, it must be something; and thus something and nothing are two sides of basic existence, or immediate Being.