A user error is an error which results from a mistake made by the user. This type of error can happen with a wide variety of systems, although people often use the term specifically to refer to computer systems, including operating systems and software programs. User errors are a perennial problem, and there are a number of ways to address them.
In some communities, there is a certain degree of snobbery about user errors. The implication is that user errors are the result of stupidity or ineptitude, as opposed to a poorly designed system, a confusing interface, or a simple innocent mistake such as typing "3" instead of "2." Opponents of this point of view argue that user errors are often the fault of the system, not the user; if a system is not intuitive or easy to use, for example, it is hardly a user's fault when she or he has difficulties with it.
In a well designed system, steps will be taken to reduce user error. For example, many websites have a search function which automatically corrects spelling errors, or which offers spelling suggestions if it suspects that a user might have made a mistake. Likewise, many interfaces will be fairly forgiving with the types of commands people use to operate the system, or will offer up warnings if they suspect that a user might be undertaking an unwise action. Systems may also be streamlined and simplified so that they are easier to understand and operate, with the goal of facilitating use at a variety of skill levels.
Other systems may be more rigid and demanding, expecting users to adhere to very precise syntax. In these systems, failsafes like prompts and warning dialogue boxes may not pop up, with the architect of the system assuming that the users will not make mistakes. Likewise, such systems may not allow users to back up if they make errors, or may not offer other ways for dealing with mistakes made. The system may not even warn the user when a user error is made, which can be frustrating when things go wrong and the user has no idea why.
Technicians called in to repair various systems may sometimes make disparaging comments about user errors if they suspect that a problem was caused by an unskilled user, or if they cannot replicate the problem because it was the result of a user error. A better approach to such issues might be offering to educate users so that they do not experience errors in the future, or asking users to demonstrate what they were doing when the user error occurred, so that the technician can figure out what happened.