Castle vs Palace
Castles are built with the primary motive of protection. Safety is the purpose for which a castle is generally built. Decoration is secondary when it comes to building a castle. Hence a castle is primarily a fortification.
A palace is built with an intention of constructing spacious halls and rooms primarily meant for comfort. Decoration is the primary intent when it comes to building a palace. The palace at Stockholm, Sweden and the palace at Mysore in India are the two best examples of palaces that are endowed with the element of decoration. As a matter of fact both have become favorite spots of tourist destination.
Castles are built in the sense of defense, whereas palaces are not built with the sense of defense. Castles can turn into places of residence as well, but the main purport in building them is defense. A palace is just nothing more than a beautiful place to live.
A building or a series of strong and well-built buildings to ensure safety of the king and the other persons concerned with the king is called a castle. In fact it is built to offer protection against the attack of the enemies and political sieges. A palace is on the other hand a building that provides leisure and diversion to the king and the other people around him.
A well-built palace is endowed with comfortable and lovely rooms and halls meant for the stay of the queens, various ministers and other people concerned with the government.
In short it can be said that a castle is built to prove supremacy, whereas a palace is built to prove royalty. Lot of money was usually spent in the construction of a palace.