It is a kind of printing technique.
The name comes from the fact that silk was originally used.
Nowadays, silk is not used. A chemical fiber mesh is put on an aluminum frame to make a silkscreen plate with parts that allow ink to pass through and parts that do not.
Make a plate for each color and each color is printed individually.Put ink on the screen and rub it with a spatula called a squeegee. First color printing → drying. The second color is printed → dried, and the colors are overlaid in this order.
The autograph and edition number written on silkscreen by the artist adds more value as a work of art. Silkscreen is still the main expression technique of contemporary art.