Ribbon takes an array of paths as input and draws lines along those paths. It uses complex logic to get the co-ordinates.
var ribbon = new BABYLON.Mesh.CreateRibbon("ribbon", paths, false, false, null, scene);
Line is a basic element in 3D games. To draw a line, you need two points between which you can draw a line.
var mesh = BABYLON.Mesh.CreateLines("lines", path, scene, true);
Tube is a curved cylinder shape. It can give different parametric shapes based on the equation (maths function) applied to it to get the co-ordinates.
var tube = BABYLON.Mesh.CreateTube(name, path, radius, tessellation, radiusFunction, cap, scene, updatable?, sideOrientation);
Extrusion helps in transforming a 2D shape into a volumic shape.
BABYLON.Mesh.ExtrudeShape(name, shape, path, scale, rotation, cap, scene, updatable?, sideOrientation)