A Decocker or decocking lever allows the hammer to be dropped on a live cartridge without discharging it, via disengaging, retracting, blocking or covering the firing pin. This eliminates the need to control the fall of the hammer, although since all mechanisms can fail it is still necessary to keep the muzzle of the gun pointed in a safe direction while operating the decocker.

Thanks unpecador.
Although my question actually refers to if the X-Five pistol especifically comes with a decocking mechanism or is there just the manual safety.

No decocker on the X-Five. It's a single action with a thumb safety.

The X-five L1, Competition, or Tactical are SAO with a thumb safety, however the X-five All Around (if you can find one) is SA/DA and has a decocking lever just like the P226.