Typo.
A typo (short for typographical error) is a small, unintentional mistake made while typing or printing text, such as misspelled words, missing letters, or transposed characters
Common examples include “teh” for “the” or “manager” for “manage”.
Please help me out – I need another 32 people to each read one chapter of my biography about Irene Mawer. Thnacks