What is "Immovable Property” under the General Clauses Act, 1897?

According to section 3 (26) of the General Clauses Act, 1897, ‘Immovable Property' shall include: (i) Land, (ii) Benefits to arise out of land, and (iii) Things attached to the earth, or (iv) Permanently fastened to anything attached to the earth. For example, trees are immovable property because trees are benefits arise out of the land and attached to the earth. However, timber is not immovable property as the same are not permanently attached to the earth. In the same manner, buildings are immovable property.