Global actions refer to several administrative actions that when taken have a global effect; that is, they affect all Wikimedia Foundation (WMF) public wikis, such as Wikipedia, Wiktionary, Wikimedia Commons, and Wikibooks, in all available languages. These wikis are all listed at Special:SiteMatrix. Global actions include global blocks, global locks, global bans, and global rights.
Full descriptions and policies can be found in pages in Category:Global actions on the Meta-Wiki site; this is brief overview only, and the relevant Meta-Wiki pages should be consulted in case of problems. The stewards handbook contains practical advice on how stewards should proceed.