Partial Shade (or part shade) is a gardening term that refers to plants that perform best in conditions of three to six hours of direct, unimpeded sunlight per day.
This definition is quite variable. It can refer to dappled light from overhead tree branches, or to the shade provided by taller plants. Taken literally, it refers to conditions of partial exposure, where direct sunlight is available for only part of the day. Planting against an east- or west-facing wall would provide these conditions.
Many plants described as preferring partial shade will perform well in full sun conditions, but may benefit from shade during mid-day to late afternoon, or in periods of prolonged drought.
Indoors, many houseplants thrive in relatively bright conditions, near a window or other light source.