One topological space can carry different orbifold structures. For example, consider the orbifold "O" associated with a quotient space of the 2-sphere along a rotation by formula_3; it is homeomorphic to the 2-sphere, but the natural orbifold structure is different. It is possible to adopt most of the characteristics of manifolds to orbifolds and these characteristics are usually different from correspondent characteristics of underlying space. In the above example, the "orbifold fundamental group" of "O" is formula_2 and its "orbifold Euler characteristic" is 1.