What is the meaning of 'Waheguru'?

Guru Ki Pyari Sadh Sangat Jeo,

There are some very important basic facts to be understood about body,
mind, life and death.
Who am I? I am not my physical body. I am divine living in the form of subtle
or sookham body(eternal) in the physical or Asthool body(perishable) . Mann
toon jot saroop hai apnaa mool pachhaan. jo brahmandy soee pinday jo khojay so
paavay.
Normally speaking, we identify ourselves with the physical body which when
perishes, we call DEATH. Actually, there is no such thing as death because the

I want to know about this Baba.I don't t know why people calls him Sant. In his smagam video I saw lot of people bow their head in front of him.

How we define Sewa?