What is the meaning of the term Sangha in the context of Buddha?

It was an organisation of Buddhist monks.

In due course, a community of disciples gathered around the Buddha, leading to the establishment of a monastic organization called the sangha. Within this sangha, monks lived a modest life, possessing only the essential requisites for survival, such as a bowl for receiving alms from the laity. Due to their dependence on alms, they came to be known as bhikkhus.

Initially, only men were allowed to join the sangha, but later, women were also admitted, thanks to the intervention of Ananda, one of the Buddha's closest disciples. Ananda persuaded the Buddha to allow women into the sangha, leading to the ordination of the Buddha's foster mother, Mahapajapati Gotami, as the first bhikkhuni. Many women who joined the sangha became adept in teaching dhamma and were revered as theris - esteemed women who had attained liberation.

The Buddha's followers hailed from various social backgrounds, encompassing kings, wealthy individuals, gahapatis, as well as humble members of society such as workers, slaves, and craftspeople. Once within the sangha, all were considered equals, having shed their former social identities upon becoming bhikkhus and bhikkhunis. The sangha's internal functioning was based on the traditions of ganas and sanghas, where decisions were reached through discussions, and if needed, by a democratic vote on the subject.