To splel a wrd worng.

Very sexy variation of misspelling. When someone misspells a word because they are incredibly stupid, that's a misspellation.

The act of misspelling a word.

A word that describes a word that isn't spelled right.

misspelling (noun, plural: misspellings)
Simply means: a wrongly spelled word (or spelt! - contrary to what many think, this isn't a misspelling, but a seldom used form of spelled).

Typos, on the other hand, refer specifically to typographical errors (of which typo is an abbreviation), which appeared with the first printing press (see Gutenberg). They generally occur in printed material, or during the use of an implement or machinery whose output is print-like in appearance (including the printing press itself, typewriters, computers and their keyboards etc.).
An example of a misspelled word would be: phoenatically, used by the person who provided the previous "definition" of the word misspellings. Correct spelling of that word is: phonetically.

The reasons for assuming that he misspelled the word, and it isn't a typo, are threefold:
1) on the keyboard, the "e" key is not in the immediate vicinity of the two adjacent letters ("o" and "n").
2) the word phonetic has its origins in ancient Greek; many Greek words (and names) use the compound vowel "oe" (such as: phoenix, Phoenicians, or perhaps the best known one: Oedipus). Hence his confusion.
3) a practical reason: he did not correct his mistake, thinking it was correct.
So much then, for the differentiation between an ignorance-induced misspelling and a printing or typing mistake known as typo.

The disgustingly proper way to say typo.

When you misspell something

Wen u spel a wrd rongly loik tis

The result of a failed attempt made by someone with only a vague idea of what the 'English Language' actually is.

Easily notable as not a typo error, as a typo is still readable in normal language. No, one who is an awful misspeller actually has no idea whatsoever how that word should be, and will try and write phoenetically.