In the context of optimization, what is the primary difference between the items in the Fractional Knapsack problem versus the 0/1 Knapsack problem?

Divisibility

In Fractional Knapsack, items can be broken into smaller pieces, allowing a greedy strategy (sorting by value/weight) to be optimal. In 0/1 Knapsack, items are indivisible, necessitating a Dynamic Programming approach.