Castles are considered guarded structures meant for nobility in the medieval era in the Middle East & European countries.
Many people debate the margin of the word "castle in modern usage, but it is generally associated as an exclusive fortified home. Castles were built between an approximate 900-year period, and had many distinctive features. This is different from a palace, which is not guarded or fortified, and from a fortress, which is not considered a residence. The term still is used loosely and tends to be used to describe buildings as different as country houses and forts.