Frattini subgroup ($\Phi (G)$)

The Frattini subgroup is an important concept in group theory, particularly in the study of finite groups. It is defined as the subgroup of a group \( G \) that is generated by all the non-generators of \( G \). Specifically, it has a few equivalent characterizations: 1. **Definition**: The Frattini subgroup \( \Phi(G) \) of a group \( G \) is the intersection of all maximal subgroups of \( G \).