WHAT IS KAALA ?
Kala is the dimension of the Universe in which the vibration component, the Parashakti component of Paramashiva is manifesting.
Just zoom out, see the space where Big Bangs and Black Holes are happening simultaneously, billions of planets, suns, moons, stars moving, taking birth, living for millions of years and disappearing simultaneously. That space is Kala.
Maha Kalabhairava is the Lord of Time and Space. As the Lord of time and integrity, he holds the key to cosmic archives - the Akashic Records which contain the past, present and future.
Kalabhairava is the source of the causal body, the source from which rejuvenation for manifestation happens.
The Kamikagama, Purva Pada, mantroddhara patalam, Verse - 24
SAYS
Swastham Thikshna Shobithakaram Shruthajanoth Dhaaram Krupasagaram
Aamnayaskarothi Karpakaram Dandam Daratnam Sada
Shri Kaasipuranayakam Sakala Mantrasya Ishwaram Mokshadam
Dhyayettam Hridhi Kalabhairava Gurum Kaantha Sametam Param.
FURTHER, THE SKANDA PURANA SAYS
At one point, Brahma the creator, falls into delusion and forgets His real identity. He originally had 5 heads, just like Mahadeva. Suddenly He fell into delusion, catching on to his false identify due to His ego and arrogance. So, Mahadeva just wakes up from His samadhi, manifests as Kalabhairava, the Lord of time, removes the false identity of Brahma and blesses Him with the Shivoham experience.
Lord Kalabhairava Bestows Abundance And Wealth
भुक्तिमुक्तिदायकं प्रशस्तचारुविग्रहं
भक्तवत्सलं स्थितं समस्तलोकविग्रहम्
Bhukti-Mukti-Daayakam Prashasta-Caaru-Vigraham
Bhakta-Vatsalam Sthitam Samasta-Loka-Vigraham
Kalabhairava Ashtakam - verse 4
(Salutations to Sri Kalabhairava) Who is the Giver of Worldly Prosperity and Liberation and Who has an Auspicious Pleasing Form. Who is Kind and Loving to His Devotees and Who Stands Firm as the deity of all lokas.