To mark last month’s World Teachers’ Day (sponsored by UNESCO , the United Nations Educational, Scientific and Cultural Organization), photographers from Reuters took pictures around the world of educators with their students in a telling exhibit of the very different circumstances under which children attend school. Here are 15 pictures taken by Reuters photographers, revealing the spectrum of “classrooms” — from those with literally no resources to those well-stocked and housed.

Teacher Mahajera Armani and her class of girls pose for a picture at their study open area, founded by Bangladesh Rural Advancement Committee (BRAC), outside Jalalabad city, Afghanistan September 19, 2015. (Reuters)

Class one children aged between six and seven years old pose for pictures in their classroom at Gifted Hands Educational Centre in Kenya’s Kibera slum in the capital Nairobi, September 16, 2015. (Reuters)

Giang Thi May teaches a first grade class at the primary school of Van Chai in Dong Van district, on the border with China, north of Hanoi, Vietnam, September 21, 2015. There is no electricity and no books. She teaches the children in the local Hmong language. (Reuters)

Teacher Father Juan Humberto Cruz poses for pictures with 4th grade students at Semillas de Esperanza (Seeds of Hope) school in Soacha, near Bogota, Colombia, June 11, 2015. (REUTERS/John Vizcaino)

Teacher Manel el Ayachi poses for a picture on the first day of a new school year at Linine Street Preparatory School in Tunis, Tunisia, September 16, 2015. (Reuters)

Third grade students attend class at the Mashal Model School on the outskirts of Islamabad, Pakistan, September 19, 2015. The Mashal Model School founded by Zeba Husain caters to children of underprivileged families from different parts of Pakistan and Afghanistan living in the village of Bari Imam who, outside of school, are street vendors, scavengers, beggars and car washers. (Reuters)

Teacher Moulay Ismael Lamrani poses for a picture with his class in the Oudaya primary school in Rabat, September 15, 2015, at the start of the new school year in Morocco. (Reuters)

A class at Tyburn Primary School in Chatsworth, Durban, South Africa, September 15, 2015. (Reuters)

Teacher Ana Dorrego poses with students of the rural school Agustin Ferreira on the outskirts of Minas city, Uruguay, September 15, 2015. The school has 12 students aged 4 to 11, with only one teacher. Activities include milking a cow, planting vegetables and cooking. (Reuters)

Teacher Elizabeth Moguel poses for a photograph with her seventh grade Latin class at Boston Latin School in Boston, Massachusetts September 17, 2015. Boston Latin School is the first and oldest public school in the U.S, founded in 1635. (Reuters)

Year 9 Biology boys class pose for a picture with teacher Suzanne Veitch in their classroom at Forest School, London, April 27, 2015. (Reuters)

Students of the 10th form of the Gymnasium 1567 pose for a group portrait together with their teacher of History, Tamara Eidelman, in Moscow, Russia, September 23, 2015. (Reuters)

Teacher Kahon Rochel poses for a picture with students inside their classroom at the the EPV Sinai primary school in Abidjan, Ivory Coast, September 28, 2015. (Reuters)

Children of the floating Municipal School Sao Jose II pose for a picture along the Amazonas River bank in a rural area of Manaus, Brazil, June 18, 2015. (Reuters)

Master Mohammad Ayoub poses with his fifth grade students at a local park in Islamabad, Pakistan September 18, 2015. Ayoub, a Pakistani civil servant, started his programme to educate underprivileged children in 1985. Ayoub provides the educational supplies from his income as a civil servant while volunteers and his students teach the children English, Urdu and maths. Their classroom is in a local park during fair weather and a room in the local slum in the rainy season. (Reuters)