Perspectives that are moving with respect to each other are said to be in different “frames”. So, something like “move to a different frame” just means “change speed”. Galileo (the famous one) recognized that in different frames the same events happen in different places (picture above). The first big result of the EEP, is that not only do different frames disagree on where events happen, but also when. There is always some frame in which spacelike separated events happen at the same time, but never in the same place.