Shiva is beyond any definitions at all. Attempting to define Shiva would be an adventure. A real Mission Impossible. Shiva can only be experienced and not intellectually understood. A bucket cannot contain the water of the ocean.
Shiva has two distinct identities in human understanding which blurs at times. Shiva as the Supreme Parabrahma and Shiva as a finite entity who is married to Goddess Parvati and has children. Shiva as the house holder represents human existence, a god with wife and children, yet supremely, spiritually powerful. He is a householder and a master at the same time. Master of masters – Supreme master and Saint of all saints – Supreme Saint. He floats with time and is timeless too.
On the other hand, Shiva as the Supreme Parabrahma is formless and beyond time and space. He is the indivisible unity. This Shiva has no beginning or end. He is Parabrahma. Shiva Linga represents that Shiva. It is multi dimensional or all-dimensional. We also worship Shiva as a finite entity who is easy to get annoyed and angry (Kshipra Kopi) and also easy to please.(Kshipra Prasadi)