What is the maximum number of edges in a directed graph with n nodes?

Question

What is the maximum number of edges in a directed graph with n nodes? Is there any upper bound?

Answer 1

There can be as many as n(n-1)/2 edges in the graph if not multi-edge is allowed.

And this is achievable if we label the vertices 1,2,...,n and there's an edge from i to j iff i>j.

See here.