Screen printing is the process of printing a design onto items utilizing a stencil made from a fine-mesh screen fabric.
Screen printing is the same process that is sometimes called "silk screening". In the past, silk was used as the fine mesh fabric from which the stencils were made. Nowadays, polyester fabric is the material of choice.
Each screen stencil can be used to print one ink color, so designs that require multiple ink colors will require multiple screens to be made.
Screen printing is most suitable for larger quantity orders and especially when the design to be printed has a limited number of colors.