You may need to do just one application, however some systems offer money saving multi-functional capabilities...
Lamination is usually applied on 1 side only with a pressure sensitive over laminate film. These films give a quality finish. Good quality pressure sensitive over laminate film is usually between 70 and 100 micron in thickness.
Encapsulating involves a heat activated thermal film being applied on both sides of the print. The finished result is trimmed to leave a clear border around the edge of the print, therefore encapsulated. Film is available in gloss and matt finishes in a range of thickness including 38, 75, 125 and 250 micron rolls.
Mounting fixes a print to a substrate/board using an adhesive. This can be permanent or semi-permanent.