|This page in a nutshell: User accounts and IP addresses may be blocked from editing to protect Wikipedia from disruption.|
Blocking is the method by which administrators technically prevent users from editing Wikipedia. Blocks may be applied to user accounts, to IP addresses, and to ranges of IP addresses, for either a definite or an indefinite time, to all or a subset of pages. Blocked users can continue to access Wikipedia, but cannot edit any page they are blocked from (including, if appropriate, their own user pages). In most cases, a site-wide blocked user will only be able to edit their own user talk page.
Blocks are used to prevent damage or disruption to Wikipedia, not to punish users (see § Purpose and goals). Any user may report disruption and ask administrators to consider blocking a disruptive account or IP address (see § Requesting blocks).
If editors believe a block has been improperly issued, they can request a review of that block at Wikipedia:Administrative action review. Administrators can unblock a user when they feel the block is unwarranted or no longer appropriate.
Blocking is different from banning, which is a formal retraction of editing privileges on all or part of Wikipedia. Blocks disable a user's ability to edit pages; bans do not. However, bans may be enforced by blocks; users who are subject to a total ban, or who breach the terms of a partial ban, will most likely be site-wide blocked to enforce the ban.