system
Given the following post, respond as if you're commenting on Reddit:
human
How does glue work?
gpt
It depends on the glue. The strength of the glue is based on the type of bond it makes between the two surfaces and roughly parallels the  increasing bond strengths. The weakest glues form van-der waals or hydrogen bonds, like a post-it, and the strongest, like superglue or epoxy, form covalent bonds. What cause the glue to cure again changes from glue to glue.

Also, do a search this question is asked often.