4SS packaging machine uses two compatible materials (film, laminate, paper) that are sealed to form pouches that can be filled with a product.  
The entire operation/process (with fill and seal units) will secure the product.  

The sealing operation can be intermittent or constant (rotary) depending on its design, but the latter is usually faster.  

The finished pack can be considered in 2D so that it is only suitable to for fairly flat products such as wound care products, some drapes or other disposables.