Un sito web è detto wiki se costruito appoggiandosi su una piattaforma o software collaborativo detto software wiki o semplicemente Wiki, che permette ai propri utenti di aggiungere, modificare o cancellare contenuti attraverso un browser web, in genere utilizzando un linguaggio di markup semplificato o un editor di testo online.

A wiki ( ) is a website which allows collaborative modification of its content and structure directly from the web browser. In a typical wiki, text is written using a simplified markup language (known as "wiki markup"), and often edited with the help of a rich-text editor.

.wiki is a top-level domain name. It was proposed in ICANN's New generic top-level domain (gTLD) Program, and became available to the general public on May 26, 2014. Top Level Design (TLD) is the domain name registry for the string.