canteen where students eat lunch and often breakfast and snacks. Athletic field, playground, gym, or track place where students participating in sports or physical education practice Schoolyards, all-purpose playfields typically in elementary schools, often made of concrete. Auditorium or hall where student theatrical and musical productions can be staged and where all-school events such as assemblies are held Office where the administrative work of the school is done Library where students ask librarians reference questions, check out books and magazines, and often use computers Computer labs where computer-based work is done and the internet accessed Cultural activities where the students uphold their cultural practice through activities like games, dance, and music Education facilities in low-income countries In low-income countries, only 32% of primary, 43% of lower secondary and 52% of upper secondary schools have access to electricity. This affects access to the internet, which is just 37% in upper secondary schools in low-income countries, as compared to 59% in those in middle-income countries and 93% in those in high-income countries. Access to basic water, sanitation and hygiene is also far from universal. Among upper secondary schools, only 53% in low-income countries and 84% in middle-income countries have access to basic drinking water. Access to water and sanitation is universal in high-income countries. Security The safety of staff and students is increasingly becoming an issue for school communities, an issue most schools are addressing through improved security. Some have also taken measures such as installing metal detectors or video surveillance. Others have even taken measures such as having the children swipe identification cards as they board the school bus. These plans have included door numbering to aid public safety response for some schools. Other security concerns faced by schools include bomb threats, gangs, and vandalism. In recognition of these threats, the United Nations Sustainable Development Goal 4 advocates for upgrading education facilities to provide a safe, non-violent learning environment. Health services School health services are services from medical, teaching and other professionals applied in or out of school to improve the health and well-being of children and, in some cases, whole families. These services have been developed in different ways around the globe. However, the fundamentals are constant: the early detection, correction, prevention, or amelioration of disease, disability, and abuse from which school-aged children can suffer. Online schools and classes Some schools offer remote access to their classes over the internet.