Press Shift-A and add a Bezier Curve.

Switch the Timeline Editor to Geometry Node Editor.

Click on the New button and add a Geometry Node modifier.

Press Shift-A and instance on Points node.

Drop the node between the Input and Output nodes.

We need a Instance object to place on the Curve control points.

Let's add a Cube object node.

Connect the Geometry to the Instance node.

As you can see, two cubes have been added.

Because the curve has only two control points.

Set the X dimension to 0.5, and set the Y dimension to 0.3.

Go to Viewport Shading menu and enable the Cavity option, and switch the type to Both.

We can increase the number of the instances on the curve.

To do that, let's add a Resample Curve node.

Drop the node after the Group Input node.

This node will create new control points on the curve.

We are in the Count mode, so, it will be added 10 instance objects along the curve.

If we set the Count value to 4, 4 instance objects will be added.

If we switch to Length mode, the instance objects will be added based on the Length value.

Let's set the Length value to 0.6.

As you can see, only 4 instance objects will be added on the curve.

It will be computed automatically how many instance objects will be along the curve at 0.6 meters intervals.

Go over the Viewport window, press Tab key to switch to Edit mode.

Select the last control point, press Numpad 7 to switch to Top view.

Hit the E key and extrude the curve.

The best thing, we can extend the curve as we wish, and the instance number will be computed automatically based on the curve length.

Let's add Join Geometry node to be able to see the curve.

As you have noticed, the instance objects don't point the same direction along the curve.

We need to rotate each instance object in the curve direction.

To do that, we gonna use Curve Tangent node.

Let's add Curve Tangent node.

This node computes the direction of the curve at every control point.

Now, we need to determine which axis of the instance will point to the curve direction.

Let's add Align Euler to Vector node.

Plug the Tangent node to Vector node, and the Rotation to Rotation node.

There we go. We have aligned the local X axis of the instances to the curve direction.

If we switch to Y axis, the local Y axis will be aligned to the curve direction.

Now, we can edit the curve as we wish.

Thanks for watching. See you in the next tutorial.