<p>A wiki is a website designed for collaborative editing, letting many people create, update, and organize content directly in a web browser.
They emphasize simplicity and openness — pages can be created or modified without special technical skills, and most maintain an edit history so revisions can be reviewed or reverted.
Common features
- **Collaborative editing:** Numerous contributors can work on pages, sometimes simultaneously.  
- **Edit history:** Each change is logged with a time and the editor’s name or IP.  
- **Interlinking:** Creating links among pages is straightforward, which helps interconnect content.  
- **Lightweight markup:** Pages are typically formatted with lightweight markup like WikiText or Markdown.  
- **Permission settings:** Access controls vary — from fully open editing to permissions for certain users or groups.  
- **Discussion pages:** Separate talk pages allow contributors to discuss edits and structure.
Frequent uses
- Community-driven knowledge bases (for example, Wikipedia)  
- Internal documentation and company knowledge bases  
- Group writing and collaborative note-taking  
- Classroom and educational projects
Pros
- **Fast collaboration:** Many people can collaborate and iterate quickly on content.  
- **Openness:** Visibility into edits and discussions shows how decisions were reached.  
- **Expandable:** They scale organically as users add more pages and topics.
Cons
- **Vandalism and false information:** Public editing can lead to vandalism or incorrect information.  
- **Inconsistent quality:** Entries may vary in accuracy, style, and completeness.  
- **Organizational issues:** Without clear governance, content may become fragmented or disputed.
Illustration
- **Wikipedia** — the largest example, maintained by the Wikimedia Foundation and contributed to by volunteers worldwide.</p>