Convex _ Non-Convex

https://www.researchgate.net/post/What_is_the_difference_between_convex_and_non-convex_optimization_problems

The basic difference between the two categories is that in

a) convex optimization there can be only one optimal solution, which is globally optimal or you might prove that there is no feasible solution to the problem, 

b) nonconvex optimization may have multiple locally optimal points and it can take a lot of time to identify whether the problem has no solution or if the solution is global. 

Hence, the efficiency in time of the convex optimization problem is much better.

For a convex optimization problem, we have only one local optimal solution which is also the global optimal solution. 

For a non-convex optimization problem, there are many local optimal solutions.