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Found by a window with a southern or southwestern exposure,  are known as the Brightest natural indoor light for houseplants.  The strongest sunrays that can come through a window are the  hottest and considered intense light, bright direct light, and full sun.

 

Medium (AKA – Shade) houseplant light refers to direct exposure from a sunny window facing an east or west direction.   Also, houseplants receiving medium light (or what's often called bright indirect) are spots near a filtered intense bright light.  (Bright direct light filtered through a curtain or the light obscured by an object placed between the houseplant and the bright direct light of southern or southwestern exposure called filtered light.

 

Found near north facing windows the illumination  equals low light or shade, with some bright exposure, partial shade.  The light several feet from an east or west window or far from a southern or southwestern exposure (in both cases, often called indirect light) also qualifies as low light.  Low light is common in corners and dark (low lit rooms).   In summary, your plants will let you know when the light is not right, because, insufficient light causes spindly leggie stems, yellowing of foliage, and leaf droppings.  Too much light causes leaf burn or pale, faded foliage..