Sri Bhairava is the guardian deity of the abode of Lord Shiva. Hence, he is also called Kshetra Pala. The term Bhairava means 'Terrific'. Sri Kala bhairava represents the protective energy of Lord Shiva, that the Lord created for protection, during the creation-dissolution cycle.
He is the manifestation who oversees the march of time. The march of time is inexorable only because Lord Kala Bhairava makes it so. As the saying goes, time lost is lost forever. There's nothing more precious than time. So intelligent humans should use every moment effectively, ane be conscious of the spiritual path. And those who want to do this, have the divine help of Lord Kala Bhairava, if they pray for it sincerely. Lord Kala Bhairava worship is very important in this Kali Yuga. He offers protection from bombs, biological and chemical poisons and evil influences.