>Whats the difference b/w cost of revenue and operating expenses?? Is one hard assets and the other labor/personnel related??

Cost of revenue contains costs that are directly needed to produce and distribute the product/service. If you are an internet software company, you need to run servers, you might need to compensate the creators on your platform (this is the case for YouTube) and you might need to pay moderators to moderate your social network. These things are "cost of revenue".

Costs for, say, management salaries or R&D engineers are not directly needed to keep the product/service running, so they are operating expenses.