These big windows exhibit advanced design and beauty, in addition to providing the interior a lighter, airier sensation.The most essential features of a real Palladian window are a big central window with an arched top, flanked on both sides by smaller sized rectangular windows or "sidelights" (windows are normally referred to as "lights" in architectural parlance).

This indicates that typically, when someone talks about a "Palladian window", what they suggest is something that has the standard features like the central arched window with smaller sidelights on either side and even simply a grand three-part window rather than anything more specific. Often, people even use "Palladian window" to refer to any big arched window.