What is p.p.t simulator? I was reading research paper Reusable Garbled circuit in which i read the term "p.p.t Simulator" and p.p.t Algorithm. I know about Probablistic Polynomial Time(p.p.t) Algorithm. Kindly someone tell me what is Probablistic Polynomial Time Simulator
A PPT simulator is really just a PPT algorithm. So if you know what a PPT algorithm is then you know what a PPT simulator is as well.

The term simulator is used in many contexts in cryptography, but typically they are PPT algorithms that are supposed to produce output according to some distribution simulating the output distributions of one or more parties in some protocol.