The 21st century began on 1 January 2001 and will conclude on 31 December 2100 according to the Gregorian calendar. It follows the 20th century and marks the era in which many societies moved decisively into the digital and networked age. Debates about its defining events and long-term consequences continue as the century progresses.

Chronology and naming

By convention there is no year zero in the Anno Domini system; centuries are counted from year 1. This is the reason the century is conventionally said to start in 2001 rather than 2000. The label "21st century" is a calendrical descriptor rather than a value judgment about cultural or technological status.

Major characteristics

  • Digital revolution: widespread internet access, mobile computing, and pervasive data networks.
  • Globalization and interdependence: expanded trade, travel, and cultural exchange alongside new forms of economic integration.
  • Environmental challenge: heightened awareness of climate change, biodiversity loss, and resource limits.
  • Geopolitical realignment: rising powers, regional conflicts, and changing international institutions.

Science, technology and economy

Advances in computing, biotechnology, and materials science have reshaped industries and everyday life. Automation, artificial intelligence, and genomic techniques have created new opportunities and ethical debates. Economically, digital platforms and global supply chains have driven growth while also producing uneven outcomes and calls for new governance models.

Society, culture and politics

Social media and instant communication have transformed how communities form and how information circulates, affecting politics, journalism, and personal life. Public health emergencies, large-scale migrations, and movements for social justice have influenced policy and public discourse. Cultural exchange has accelerated even as local identities and tensions persist.

Environment and long-term issues

Climate change and ecological pressures are central long-term challenges, prompting technological responses such as renewable energy and adaptation planning. The century is likely to be judged by how societies manage sustainability, equity, and resilience in the face of planetary-scale risks.

Notable distinctions

Unlike earlier centuries defined by a single dominant power or technology, the 21st century is characterized by rapid change across many domains simultaneously. Its story continues to unfold, shaped by technological innovation, political choices, and collective responses to global problems.