Wildlife sanctuary is a natural area which is used for keeping the particular species of animals, especially the endangered ones. Sanctuary is a place which is suitable for protection and development of wildlife or its environment.
The suitability is determined by judging the ecological, floral, faunal, geomorphological factors associated with the area.
National park is also very similar to a wildlife sanctuary, as it is also declared reserved for the protection and development of wild life. Therefore, many people consider them synonymous. The main difference between the two is that in a sanctuary, some other activities may be allowed, whereas in a National park no other activities are allowed. For example, the people may possess rights for timber extraction in a wildlife sanctuary, but this right is not provided under the premises of a national park.
National parks have a proper boundary, whereas the wildlife sanctuaries usually do not have properly marked boundaries. In context to ownership rights, one may retain the private ownership rights if it is not affecting the cause of wildlife conservation. On the other hand, any type of private ownership rights does not exist in a national park.