What are star spikes and how can I achieve them in my images?

Star spikes are diffraction patterns created by light passing through the aperture blades of a lens or telescope, resulting in elongated star shapes. They can add visual interest to astrophotography images, especially when photographing point light sources like stars. To achieve star spikes, use a lens or telescope with aperture blades and adjust the aperture setting to create diffraction spikes around bright stars during long exposures.