I have tried reading certain google results to my question but I am still not clear
please kindly explain in simple words with examples, what is the difference between convolution and multiplication? And if they both are the same, under what condition?
The ordinary multiplication looks at the current time only: $$(f \cdot g)(x) = f(x) \, g(x)$$
The convolution looks at different times: $$(f * g)(x) = \int_{-\infty}^{\infty} f(y) \, g(x-y) \, dy$$