what is the difference between substrate level phosphorylation and oxidative phosphorylation?

Hi Saumya,
Thank you for asking

I am explaing in very simple and lucent way.

Phosphorylation is related with the phosphoryl group transfer from one species to another. But more specifically this term is used to denote fromation of ATP.

Substrate-Level phosphorylation: When ATP (or GTP) forms from ADP and inorganic phosphate. It normally occurs during glycolysis in the cytoplasm. It is the direct phosphoryl group transfer. It doesnot depends upon electron transport chain

Oxidative phosphorylation:It takes placce along the electron transport chain deriving the energy from NADH2 FADH2 trough the event of chemiosmosis where ATP is synthesized indirectly from the creation of a proton gradient and the movement of these protons back cross the membrane.

Hope the answer of the question