limit and colimit
- limit (of a graph in category
)-final object of the cone category (w.r.t. the graph)-gluing (graph as well)
eg. pullback; topological product - colimit/direct limit-initial object of the cocone category-restriction
eg. disjoint union; wedge product; stalk is the colimit of presheaf; for locale, the finite intersection reserves the colimit/arbitrary union; pushout
so they both have universal property.