Handbooks are books for remembering things. Manual can be diary, bookkeeping book, reading notebook, etc. Functionally, it is mainly divided into recording and planning. Recording, as the name implies, is to write down everything you want to record.
We can put the manual together and put some lovely stickers on it, and the recorded content looks particularly interesting and lovely in it, thus increasing the frequency of our use of the manual. There are also some materials dedicated to manuals. For people who control manuals, they will prepare a variety of materials to record all their daily events. Different things will make different manuals and may have different styles.
I am also a person who likes manuals very much, but my hands-on ability is not strong, so I like to appreciate other people's manuals.