I don't know if you mean the nouns or the verbs. Let's begin with nouns (=substantives = noms).
In English, there is a noun: "a notice." A notice is a written document. It might be mailed to you. It might be posted on a board. It is called a "notice" because it is something you are supposed to pay attention to. It is like a warning, but not as strong. A notice might say "The library will be closed on September 2nd for Labor Day."
There is no noun "inform." There is no such thing as "an inform."
In English, there are also two verbs, "to notice" and "to inform." They mean very different things. I "notice" something when I pay attention to it. I "notice" something when I become aware of it. For example, my shoe feels loose. I look down. I notice that my shoelace is untied.
"To inform" means "to communicate important information to someone." The newspaper informs me of the news of the day. My watch informs me of the right time. My wife knows everything that is going on; she is well-informed.
My wife might inform me that my shoelace is untied. "Hey, Dan, your shoelace is untied!" I might reply, "Oh, thank you. I hadn't noticed that."
The following conversation is crazy--but it makes perfect sense:
Ray: There's a new notice on the notice board.
Dan: Really? I hadn't noticed the new notice.
Ray: It says: "We are happy to inform all employees that we now be having 'casual Fridays' all summer. You may wear jeans to work."
Dan: That's good information, thank you for informing me.