Non- (not)
Non-
Not; without.
The school library has a big shelf of non-fiction books.
Non-stick
Made so that food does not stick.
Aarav made dosas on a non-stick pan.
Nonsense
Words or ideas with no sense.
The ghost story was nonsense, but we laughed anyway.
Remember: Non- is often hyphenated in British English (non-stick, non-fiction), but some words are joined: nonsense. When unsure, check a dictionary.