Decades of slow but steady progress in educating more children around the world abruptly ended in 2020. By April, an unprecedented 1.4 billion students were shut out of their pre-primary, primary, and secondary schools in more than 190 countries, in an effort to slow the spread of the novel coronavirus. As the pandemic persisted, schools in some countries or jurisdictions reopened for in-person teaching, or opened for some students, while elsewhere schools have remained closed ever since with learning to greater or lesser extent taking place online or otherwise remotely. In some places, there have been waves of schools opening only to close again. An estimated 90 percent of the world’s school-aged children have had their education disrupted by the pandemic.