What is the difference between class activation map (CAM) and saliency map ?
Hi, @Ashutosh60, and welcome to the community! 
They are two different methods to achieve the same thing. Sometimes you may see people saying that CAM is a variant of saliency maps. CAM and Grad-CAM are more robust compared to vanilla gradient saliency maps. You may find more info here.
Hope that helps. Let me know if you have any more questions.