Morphology refers to the internal structure and formation of words. It is the study of the meaning of words and how to relate sounds to the meaning of words. A morpheme is the most basic unit of structure in linguistics - a basic element of meaning or a basic form.
Conversion is a process in morphology by which speakers of a language change or modify the meaning of words or the base form of words (morphemes). There are two basic kinds of morphological processes: concatenative (combining morphemes) and non-concatenative (modifying the internal structures of the morphemes). Conversion is considered to be in the latter group.
There is a great explanation of this at the link below, which a professor of linguistics has posted online to share. This link gives examples which you should find helpful.