when I apply RZ(pi/2) on ket 0 my state vector is [ 0.707-0.707j, 0+0j ]
when I apply S gate on Ket 0 my state vector is [ 1+0j, 0+0j ]
but S gate is nothing but RZ(pi/2) though they are same when we take out the global phase factor
[ 1+0j, 0+0j ]
Hi @phani.bharath , welcome to the Forum!
Yes, the key here is in the fact that with the S gate here we factor out the global phase.
I hope this answers your question! Let me know if you have additional questions.