Autocomplete is a feature provied by many source code text editors, word processors, and web browsers. Autocomplete involves the program predicting a word or phrase that the user wants to type in without the user actually typing it in completely. This feature is effective when it is easy to predict the word being typed based on those already typed, such as when there are a limited number of possible or commonly used words (as is the case with email programs, web browsers, or command line interpreters, or when editing text written in a highly-structured, easy-to-predict language, such as in source code editors). Autocomplete speeds up human-computer interactions in environments to which it is well suited.