A typographical error (also known as a misprint) is a mistake (such as a spelling mistake) committed in the typing of printed (or electronic) content. The majority of typos are caused by the simple repetition, omission, transposition, or substitution of a few characters. In some cases, however, they can also be caused by misuse or distortion of the keyboard. Typographical errors can occur anywhere within a document using your standard typewriter keys, including on title pages and abstracts. They can also appear in running heads (small labels that appear at the beginning of each page of an article). For example, if an editor were to type the word "to" instead of "too", this would be considered a typo. They are usually corrected during production editing but may not be noticed until later. A final copy may therefore differ significantly from the original version. Typos can cause confusion when reading or quoting from old texts because they can lead the reader to believe that certain words do not exist or have different meanings than what was intended. For example, a typo in which "their" is replaced with "there's" could cause someone reading this sentence today to think that I meant for there to be no more questions rather than asking whether anyone had any questions before moving on to another topic. Typos can also be used as a writing technique, especially by young authors who need to polish their work before submitting it.