Defining Sangha

“Sangha. Community. This word has two levels of meaning: (1) on the ideal (arya) level, it denotes all of the Buddha’s followers, lay or ordained, who have at least attained the level of srotapanna; (2) on the conventional (samvtri) level, it denotes the orders of the Bhiksus and Bhiksunis”
Some lay practitioners in the West these days use the word "Sangha" as a collective term for all Buddhists, but the Pali Canon uses the word parisā (Sanskrit, parisad) for the larger Buddhist community — the monks, nuns, lay men, and lay women who have taken the Three Refuges — reserving ‘Sangha’ for a more restricted use.”
“The two meanings overlap but are not necessarily identical. Some members of the ideal Sangha are not ordained; some monastics have yet to acquire the Dharma-eye”
“Unlike the present Sangha, the original Sangha viewed itself as following the mission laid down by the Master, viz, to go forth ‘…on tour for the blessing of the manyfolk, for the happiness of the manyfolk out of compassion for the world, for the welfare, the blessing, the happiness of deva and men"