What is the difference between Kruskal's and Prim's?

What is the difference between Kruskal's and Prim's?

Approach: Compare edge-focused and vertex-focused growth.

Kruskal's sorts all edges and builds a forest that eventually merges into a tree. Prim's grows a single tree from a starting vertex by adding the closest neighbor.

Follow-up: Which is better for dense graphs?

Key concepts: forest, single tree, sorting.