Cloud computing and on$-$premises computing represent two distinct models for managing and operating IT infrastructure. While there are many differences between these models, please identify the most significant ones: $1)$ Identify TWO most crucial differences between cloud computing and on$-$premises computing; $2)$ Justify your selection of these differences over others. Why do you believe these two differences are more significant than others in terms of their impact on businesses, operations, and IT strategy; and $3)$ analyze and explain the underlying causes of these differences. What technological advancements, economic factors, or shifts in business needs have led to these differences between cloud and on$-$premises computing?