samsaara vrksham aarudhaah
patanto narakaa arnave
yena cha ivo ddhrtaah sarve
tasmai shri gurave namaha

Salutations to Shri Guru, who indeed saved all
(the devoted ones) who climbed the tree of the mundane
world and were falling into the ocean of hell. 

gurur brahmaa gurur vishnu
gurudevo maheshvarah
gurur eva para brahma
tasmai shri gurave namaha

The Guru is Brahma. The Guru is Vishnu. The Guru is Lord Shiva.
The Guru is indeed Parabrahma. Salutation to Shri Guru.  

hetave jagataam eva
samsaara ar nava setave
prabhave sarva vidyaanaam
shambhave gurave namaha

Salutations to the Guru, who is Shiva, who is the only cause of
the universe, who is the bridge (by which) to cross the ocean
of the world, and who is the master of all knowledge.