Rudrabhishek is a ritual in which a Panchamrut is offered to Lord Shiva along with mantras to grant all of the wishes of the individual who performs it. This Rudrabhishek bestows wealth, the satisfaction of all desires, the removal of negativity, the cutting off of bad karma, and overall Happiness. The devotees enchant mantras/Shlokas for communicating with God.
Rudrabhishek is the way of offering prayers to Lord Shiva, Mahashivratri is important festival for Shiva bhakhts for performing Maha Rudrabhishekham. Rudrabhishek is one of the most important rituals to perform during Mahashivratri.
Rudra is the sun and moon's eyes, the wind's breath and the Vedas' voice, and the universe's heart; the world arises from his foundation. Rudra appears in the Vedas and is thought to refer to Lord Shiva's terrifying, violent, and destructive nature.