# Center (mathematics)

From Ref

Typically used for an element or a subset in a set with additional structure, satisfying certain special *core* properties.

### In group theory

**Center of a group**: The set of those elements of the group that commute with every element of the group. It forms a subgroup, in fact, a characteristic subgroup.

**Primary subject wiki entry**: Groupprops:Center

**Also located at**: Wikipedia:Center (group theory)

### In ring theory

**Center of a ring**: The set of those elements of a (usually unital) ring that commute with every element of the ring. The center of a ring is a subring; for a unital ring, it is a subring containing the multiplicative identity.

**Primary subject wiki entry**: Noncommutative:Center of a ring