While some words admit multiple spellings, some spellings are not considered standard, and thus labeled as misspellings. A misspelled word can be a series of letters that represents no correctly spelled word of the same language at all (such as "leik" for "like") or a correct spelling of another word (such as writing "here" when one means "hear," or "no" when one means "know"). Misspellings of the latter type can easily make their way into printed material because they are not caught by simple computerized spell checkers.
Misspellings may be due to either typing errors (e.g. the transposition error teh for the), or lack of knowledge of the correct spelling.