Cinema 4D Program Documentation Reference Cinema 4D Basic Features Mesh Menu
Function available in CINEMA 4D Prime, Visualize, Broadcast, Studio & BodyPaint 3D

Triangulate

Triangulate converts all of an object’s polygons to triangles. It analyses polygon selections (only these will be subdivided). In all other modes, the entire object will be triangulated.

As described Polygon Object, you should mainly work with quads. Quads are calculated faster, require less memory and produce better results for Phong shading and when used with Subdivision Surfaces.