I don't know how to express my question. I want to know what are bonds like 1.4 bond between molecules. I've read somewhere like the amylase enzyme can break 1.4 bond. I want to know what are these bonds and what are their benefits and where can I find more info about them?
Amylase breaks the bond between two sugar molecules in a chain (the chain is called starch).
The type of bond is called a glycosidic bond which is just a covalent bond between sugar molecules.
The "1.4" bond you are talking about is normally written "1,4" or "1-4"; you could interpret it as "1 to 4" because it is referring to a bond involving the first and fourth carbons of the sugar (they aren't bonded directly, there is an oxygen in between); they are just numbered that way so that (bio)chemists can talk about the molecule - see this other Q&A from Chemistry about the numbering of the carbons of glucose.