add details about your objective. Tell what your parents already have in the way of hardware [one desktop, tablet and cell phones] and what deficiency exists in their ability to use adequately [need plug and play, but I can guide them if needed]. If they just have a modem allowing only one device to be connected and want more, you'd need a router. If they have a router without wireless capability, you add a wireless access point [what do you mean? both the deviced I mentiones are wireless, right?]. If they have only a modem but have more than one PC and need wireless, you can use the wireless router. So the answer depends on what is already in place and what you want to do that you cannot do now.