Greetings are sentences expressing wishes, such as "Good luck" and "Happy New Year". Spells are formulas or spells used for execution, such as "spells" and "prayers"; Swearing is insulting or abusive language, such as "asshole" and "bitch".

The similarities and differences between them are as follows:

1. Similarity: both are a kind of language expression, which can convey certain information and emotions.

2. Difference: greetings are positive, spells are effective, and swearing is insulting or insulting. Blessing is a blessing to others, spells are for yourself, and curses are used to attack others.

To sum up, the similarities and differences between greetings, incantations and curses lie in the different information and emotions they express and the different occasions they are used.