Adha, a period of "communal enjoyment" for Muslims worldwide, has officially arrived. Here's what we've learned about the Islamic holiday.

Under the damaged dome of al-Albani Mosque in Khan Younis, families stood on broken stone and dust, raising their voices in takbir, the declaration of god's greatness, to mark the first morning of Eid al-Adha on Friday.

Adha, the festival of sacrifice by offering prayers in mosques and open spaces before sacrificing animals. (AP video by Muhammad Farooq, Shonal Ganguly and Al Emrun Garjon)